How we calculate: Finance

Total paid hours per year = hours per week × paid weeks per year. Annual salary = hourly rate × total paid hours (or, converting the other way: hourly rate = annual salary ÷ total paid hours). Weekly = hourly rate × hours per week. Bi-weekly = weekly × 2. Monthly = annual ÷ 12.

This is a gross-pay conversion only, using the standard 40×52 = 2,080-hour full-time convention, adjustable here for part-time schedules or unpaid time off. It does not account for overtime pay, employer-specific paid-time-off patterns, holidays, bonuses, or tax withholding — actual take-home pay will differ. Paid weeks per year should reflect actually-paid time, so if your 'time off' is itself paid (most salaried PTO), you'd typically still count it as a paid week.

• U.S. Bureau of Labor Statistics — How the Government Measures Unemployment (full-time hours convention) — accessed 2026-08-30

From markup: selling price = cost × (1 + markup % ÷ 100); profit = price − cost; margin % = profit ÷ price × 100. From margin: selling price = cost ÷ (1 − margin % ÷ 100); profit = price − cost; markup % = profit ÷ cost × 100.

Margin can never reach or exceed 100%, since that would require a selling price with zero or negative cost — the calculator rejects a margin input at or above 100%. Markup divides profit by cost; margin divides the same profit dollars by the larger selling price — so margin % is always smaller than markup % for any profitable sale. A 50% markup is only a 33.3% margin, not 50%; reaching an actual 50% margin requires a 100% markup instead.

• Investopedia — Markup vs. Margin: What's the Difference? — accessed 2026-08-30

Amount subject to deductible = min(bill, deductible) — you pay 100% of this. Remaining after deductible = bill − that amount. Coinsurance owed = remaining after deductible × coinsurance %. Your total payment = min(deductible amount + coinsurance owed, out-of-pocket max) — capped so you never pay more than the OOP max in a plan year. Insurance pays the rest.

Models the standard in-network deductible → coinsurance → out-of-pocket-max waterfall used by most US health plans (verified against HealthCare.gov's own worked example). It doesn't model flat-dollar copays (which typically also count toward the OOP max in real plans), separate out-of-network cost-sharing tiers, family-vs-individual deductible/OOP structures, or $0-cost-sharing preventive care. Premiums are a separate ongoing cost and aren't included here. Check your plan's Summary of Benefits and Coverage for exact numbers — this is an estimate, not a bill.

• HealthCare.gov — How to pick a health insurance plan (deductible/coinsurance/out-of-pocket maximum worked example) — accessed 2026-08-30

Self-employment tax follows the same calculation as the Self-Employment Tax Calculator (92.35% net-earnings factor, 12.4% Social Security up to the wage base, 2.9% Medicare, +0.9% Additional Medicare above $200,000). Half of the regular 15.3% SE tax is deducted above the line before computing federal income tax on the 2026 single-filer brackets with the standard deduction. Total estimated tax = federal income tax + SE tax; quarterly payment = total ÷ 4. Safe harbor annual payment = the smaller of 90% of this year's estimated tax, or 100% (110% if prior-year AGI exceeded $150,000) of last year's total tax liability.

Models a single filer using the standard deduction, federal income tax, and federal SE tax only — no state estimated tax, itemized deductions, QBI deduction, or other filing statuses. Paying at least the safe-harbor amount each quarter avoids the IRS underpayment penalty even if actual liability is higher.

• IRS — Estimated Taxes (Form 1040-ES, quarterly due dates and safe harbor rules) — accessed 2026-08-30

Regular hours = min(hours worked, 40). Overtime hours = max(0, hours worked − 40). Overtime rate = regular rate × 1.5. Regular pay = regular hours × regular rate. Overtime pay = overtime hours × overtime rate. Total pay = regular pay + overtime pay.

Models only the federal FLSA weekly standard: time-and-a-half after 40 hours in a single workweek, for a non-exempt hourly employee. Some states have stricter rules this tool doesn't apply — California, for example, also requires 1.5× pay after 8 hours in a single day (and 2× after 12), which can trigger overtime even in a week under 40 total hours. It also doesn't fold bonuses/commissions into the 'regular rate' (which federal law technically requires for overtime calculations) or model exempt-employee classification. Check your state's labor law if it may be stricter than federal.

• U.S. Department of Labor — Overtime Pay (FLSA) — accessed 2026-08-30

EMI = P × r × (1+r)ⁿ ÷ [(1+r)ⁿ − 1] P = principal, r = monthly interest rate, n = number of monthly payments The standard fixed-rate amortizing-loan formula, derived from the present-value-of-an-annuity equation used across fixed-income lending — the same math the CFPB describes for how a mortgage or installment loan pays down.

• Consumer Financial Protection Bureau — How does paying down a mortgage work? — accessed 2026-08-20

Loan amount = Home price − Down payment Monthly payment uses the standard amortization formula applied to that loan amount Same present-value-of-an-annuity formula used for any fixed-rate amortizing loan — see the CFPB's consumer explainer on how mortgage paydown works.

• Consumer Financial Protection Bureau — How does paying down a mortgage work? — accessed 2026-08-20

A = P(1 + r/n)^(nt) plus the future value of any monthly contribution series added on top The standard compound-interest formula, as explained in the U.S. SEC's Investor.gov educational materials — A is the future balance, P the principal, r the annual rate, n the compounding frequency per year, and t the number of years.

• Investor.gov (U.S. SEC) — What is compound interest? — accessed 2026-08-20

Interest = (Principal × Rate × Time) ÷ 100 Total payable = Principal + Interest The standard simple-interest formula (I = PRT), the textbook counterpart to the compound-interest formula used in the Compound Interest Calculator.

• Wolfram MathWorld — Simple Interest — accessed 2026-08-29

ROI = ((Final value − Initial investment) ÷ Initial investment) × 100 CAGR = ((Final value ÷ Initial investment)^(1/years) − 1) × 100 Standard return-on-investment and compound annual growth rate formulas, the common metrics used to measure and compare investment performance across different holding periods.

• Wikipedia — Return on investment — accessed 2026-08-29
• Wikipedia — Compound annual growth rate — accessed 2026-08-29

Net = Gross × (1 − (Tax rate % + Other deductions %) ÷ 100)

• Wikipedia — Net income (individuals) — accessed 2026-08-29

Tip = Bill × (Tip % ÷ 100) Per person = (Bill + Tip) ÷ Number of people

• Wolfram MathWorld — Percent — accessed 2026-08-29

Each person's share = Σ(price of items they're assigned ÷ number of people sharing that item), then scaled by (1 + tax/tip %)

• Wolfram MathWorld — Percent — accessed 2026-08-29

Uses the same EMI formula as the Loan EMI calculator, then tracks the running balance month by month to show how the principal/interest split shifts across the loan's life. Same present-value-of-an-annuity amortization math described in the CFPB's guide to how mortgage/loan paydown works, applied month by month rather than as a single payment figure.

• Consumer Financial Protection Bureau — How does paying down a mortgage work? — accessed 2026-08-20

Future value = current savings compounded to retirement age, plus the future value of monthly contributions Estimated monthly income = (Projected balance × 4%) ÷ 12 The 4% figure traces to William Bengen's 1994 study "Determining Withdrawal Rates Using Historical Data" (Journal of Financial Planning), which found a 4% first-year withdrawal, adjusted for inflation thereafter, held up across historical 30-year U.S. market periods for a 50-75% stock portfolio. It's a widely cited planning heuristic, not a guarantee for any individual's actual portfolio or timeframe.

• Bengen WP — Determining Withdrawal Rates Using Historical Data (Journal of Financial Planning, Oct 1994) — accessed 2026-08-23

Tax = Σ (income within each bracket × that bracket's rate), applied progressively from the lowest bracket upward

Bracket rates are published tax-year figures for each of the five jurisdictions covered (India FY 2026-27 New Regime, USA 2026 single-filer federal, UK 2026/27, Canada 2026 federal-only, Australia 2026-27 resident individual), but this tool applies them to gross income only — it does not subtract India's Section 87A rebate or standard deduction, the UK's Personal Allowance taper above £100,000, US standard deduction/credits, Canada's provincial tax layer, Australia's Medicare levy, or any other regime-specific allowance/surcharge. Your actual liability will differ. Always confirm with your local tax authority.

• IRS — Tax inflation adjustments for tax year 2026 (Rev. Proc. 2025-32) — accessed 2026-08-20
• Income Tax Department (India) — New vs Old Tax Regime FAQs — accessed 2026-08-20
• GOV.UK — Income Tax rates and Personal Allowances — accessed 2026-08-26
• Canada.ca — Canadian income tax rates for individuals (current year) — accessed 2026-08-26
• Australian Taxation Office — Tax rates, Australian resident — accessed 2026-08-26

Net cost of buying = all cash paid (down payment + monthly principal & interest + tax + insurance + maintenance) − net sale proceeds (home value − remaining loan balance − selling costs) at the chosen horizon Net cost of renting = total rent paid − the future value of the down payment if it had been invested instead Whichever net cost is lower is the cheaper option over that horizon. This opportunity-cost framing — crediting the buyer with home equity but crediting the renter with investment growth on the money they didn't tie up — is the same approach the CFPB points to when it notes that many mortgage calculators only account for principal and interest, missing tax, insurance, maintenance, and what the down payment could otherwise have earned.

• Consumer Financial Protection Bureau — Making the decision to rent or buy — accessed 2026-08-25

Front-end limit = 28% × gross monthly income (covers principal, interest, tax, and insurance — PITI) Back-end limit = 36% × gross monthly income − other monthly debts Maximum monthly housing budget = the smaller of the two The maximum home price is then solved so that its principal & interest payment plus its estimated tax and insurance exactly fill that monthly budget, given your down payment, rate, and term. Widely known as the 28/36 rule — a guideline, not a law, that most conventional mortgage underwriting still references.

• Bankrate — What is the 28/36 rule? — accessed 2026-08-25

Amount financed = vehicle price + sales tax − down payment − trade-in value Monthly payment = P × r × (1+r)ⁿ ÷ [(1+r)ⁿ − 1] P = amount financed, r = monthly interest rate, n = number of monthly payments The same present-value-of-an-annuity formula as any other fixed-rate amortizing loan — see the Loan EMI calculator's sourcing for the underlying math. Sales tax here is estimated on the price minus trade-in, the common convention in many (not all) US states — some states tax the full price regardless of trade-in, so treat the tax estimate as approximate for your state.

• Consumer Financial Protection Bureau — How does paying down a mortgage work? — accessed 2026-08-29

Monthly payment = P × r × (1+r)ⁿ ÷ [(1+r)ⁿ − 1] P = loan balance, r = monthly interest rate, n = number of monthly payments The standard fixed-rate amortizing-loan formula — same math as the Loan EMI and Auto Loan calculators. This models the Standard Repayment Plan (a fixed payment over a fixed term) only. Income-driven repayment plans size the payment to a percentage of income instead, and U.S. federal student loan repayment options are in active transition for 2026 — see the note below.

This does not model income-driven repayment (IDR) plans or the new Repayment Assistance Plan (RAP) introduced for 2026 — those size your payment to a percentage of income rather than a fixed schedule, and the rules governing them are changing this year. If you're on or considering an income-driven plan, use the official calculator at studentaid.gov rather than this one.

• Wikipedia — Student loans in the United States (Standard Repayment Plan) — accessed 2026-08-29

Each month: interest = balance × (APR ÷ 12), then the payment is applied to the balance plus that interest, repeated until the balance reaches zero. If the payment doesn't exceed that month's interest charge, the balance never shrinks — the calculator detects and reports this rather than showing a misleading payoff date. Same underlying amortization relationship as any other revolving or installment loan — see the Loan EMI calculator's sourcing. Card issuers calculate their own minimum payment differently (commonly a percentage of the balance plus a floor, though this varies by issuer per the CFPB), so this tool asks for your actual payment rather than guessing your card's specific minimum-payment formula.

• Consumer Financial Protection Bureau — How to reduce your debt — accessed 2026-08-29

Employee contribution = salary × contribution %, capped at the IRS annual limit Employer match = salary × min(contribution %, match cap %) × match rate Balance grows each year as: balance × (1 + return) + (employee + employer contributions) The 2026 IRS employee elective-deferral limit is $24,500 (there are additional catch-up limits for ages 50+ and 60-63 under SECURE 2.0, not modeled as separate inputs here — see the FAQ).

• IRS — 401(k) limit increases to $24,500 for 2026 — accessed 2026-08-25

Break-even point (months) = total closing costs ÷ monthly savings Monthly savings = current monthly payment − new monthly payment Both monthly payments use the standard fixed-rate amortizing-loan formula. If refinancing doesn't actually lower your payment, there's no break-even point to calculate — the calculator reports that plainly rather than showing a nonsensical negative number.

• Chase — Calculating the break-even point when refinancing — accessed 2026-08-25

Every debt's minimum payment is made each month; any extra budget is routed entirely to one priority debt at a time — the highest-APR debt under the avalanche method, or the smallest-balance debt under the snowball method — until that debt is paid off, at which point its former payment amount (minimum plus any leftover extra) rolls onto the next priority debt. This is the standard mechanic behind both named strategies, as described by the CFPB's own debt-reduction guidance.

• Consumer Financial Protection Bureau — How to reduce your debt — accessed 2026-08-25

Needs target = income × 50% Wants target = income × 30% Savings target = income × 20% The 50/30/20 rule, popularized by Elizabeth Warren and Amelia Warren Tyagi in their 2005 book 'All Your Worth: The Ultimate Lifetime Money Plan' — a rule of thumb, not a formula tied to any single household's actual costs.

• The Balance — The 50/30/20 Budget Rule of Thumb — accessed 2026-08-25

Future value of contributions = X × [((1+r)ⁿ − 1) ÷ r] × (1+r) — the standard future-value-of-an-annuity-due formula, treating each year's contribution as invested at the start of that year Roth after-tax value = future value (withdrawals are tax-free) Traditional after-tax value = future value × (1 − retirement tax rate) This compares the same nominal annual contribution amount in both accounts — it does not model investing the extra tax refund a Traditional contribution generates today, which is a real but smaller secondary effect some more detailed comparisons include.

The 2026 IRA contribution limit is $7,500 combined across all Traditional and Roth IRAs you own ($8,600 if you're 50 or older) — this calculator caps the modeled contribution at $7,500 and flags it if your entry exceeds that.

• Vanguard — Roth IRA income and contribution limits for 2026 — accessed 2026-08-25

Net worth = total assets − total liabilities Standard arithmetic on the numbers you enter — the value comes from tracking this figure consistently over time, not from the formula itself.

• Wikipedia — Net worth — accessed 2026-08-29

Target = essential monthly expenses × number of months of coverage The CFPB deliberately doesn't prescribe one fixed number of months — its own guidance frames the right target as depending on your situation and the kinds of unexpected expenses you're most likely to face. The 3-6-9 month range offered here reflects the commonly cited industry rule of thumb, not an official CFPB figure.

• Consumer Financial Protection Bureau — An essential guide to building an emergency fund — accessed 2026-08-25

Each region uses its own real mechanism, not one formula stretched across all of them: US — long-term gains use the 2026 single-filer capital-gains brackets (0%/15%/20%), short-term gains use the ordinary income brackets; both stack on top of other income. UK — Capital Gains Tax applies the same 18%/24% rates regardless of holding period, after subtracting the £3,000 Annual Exempt Amount from the gain. Canada — no separate CGT: 50% of the gain (the "inclusion rate") is added to ordinary income and taxed at your federal marginal rate, regardless of holding period. Australia — no separate CGT: assets held over 12 months get a 50% CGT discount (only half the gain counts as assessable income); held 12 months or less, the full gain counts. Either way it's then taxed at your marginal rate. India — modeled for listed equity/equity mutual funds specifically: long-term (over 12 months) gains above a ₹1.25 lakh exemption are taxed at a flat 12.5%; short-term gains at a flat 20%, with no exemption and no stacking on other income.

Figures are federal/national-level only — state, provincial, or sub-national capital gains taxes aren't included anywhere. US: single-filer only; high earners may also owe the 3.8% Net Investment Income Tax on top of this estimate, see the FAQ. India: modeled for listed equity only — property, gold, and unlisted shares use different rates and a 24-month holding threshold, not covered here. A visitor whose region isn't sourced yet sees a general/US estimate with a visible disclaimer, not a silent guess.

• Kiplinger — IRS updates capital gains tax thresholds for 2026 — accessed 2026-08-25
• GOV.UK — Capital Gains Tax rates — accessed 2026-08-29
• Scotia Wealth Management — Cancellation of the proposed capital gains inclusion rate increase (Canada) — accessed 2026-08-29
• Wilson Pateras — The 50% CGT Discount, explained (Australia) — accessed 2026-08-29
• Axis Max Life — Capital Gains Tax India, listed equity rates post-Budget 2024 — accessed 2026-08-29

Taxable earnings = net profit × 92.35% Social Security portion = min(taxable earnings, $184,500) × 12.4% Medicare portion = taxable earnings × 2.9% Additional Medicare Tax = max(0, taxable earnings − $200,000) × 0.9% (single filer) The 92.35% factor and the split rates come directly from IRS Schedule SE — it exists because a traditional employee's employer pays half of FICA tax on their behalf (7.65%), income a self-employed person never has withheld in the first place, so the 15.3% combined rate applies to a slightly reduced base instead.

Only federal self-employment tax is estimated here — this is in addition to, not instead of, federal and state income tax on the same profit. Only the 'regular' 15.3% (Social Security + Medicare) portion gets the above-the-line half-deduction; the 0.9% Additional Medicare Tax is never deductible.

• Payroll.org — Social Security wage base increases to $184,500 for 2026 — accessed 2026-08-25

Coverage need = Debt + (Annual income × years of replacement) + Mortgage balance + Education costs − existing savings & coverage The DIME method (Debt, Income, Mortgage, Education), a named approach used across the life insurance industry as a more specific alternative to flat income-multiple rules of thumb, since it accounts for your actual obligations rather than a single generic multiplier.

• NerdWallet — How much life insurance do I need? — accessed 2026-08-25

Annual property tax = assessed value × local effective tax rate Property tax rates are set entirely locally (by county, city, and school district), not federally — this is simple arithmetic on the rate you supply, not a lookup of your specific jurisdiction's actual rate.

"Assessed value" is often not the same as market value — many jurisdictions apply an assessment ratio, cap annual increases (like California's Proposition 13), or reassess only periodically. Check your county assessor's site for your property's actual current assessed value rather than assuming it equals what you'd sell the home for.

• Tax Foundation — property tax rates by state — accessed 2026-08-25

Available equity = (home value × max CLTV%) − existing mortgage balance Monthly payment uses the standard amortizing-loan formula (the same one behind this site's own Mortgage Calculator) applied to the available-equity amount, rate, and term you enter — modeling it as a fixed-term home equity loan rather than a revolving HELOC line, since a line of credit's payment depends on how much of it you actually draw and when.

Most lenders cap combined loan-to-value (existing mortgage + new borrowing, divided by home value) at 80-85%, though this varies by lender and credit profile. A HELOC itself is usually a variable-rate revolving line, not a fixed-payment loan — this calculator's payment estimate assumes you borrow and repay the full available amount as a fixed-rate home equity loan instead, which is the more predictable of the two products to model.

• Experian — How much can you borrow with a HELOC? — accessed 2026-08-25

Closing costs ≈ loan amount × 2% to 5% Covers lender fees (origination, application, underwriting), third-party fees (appraisal, title search and insurance, credit report), recording fees, and prepaid items (homeowners insurance, property tax escrow) — the commonly cited range across mortgage-industry sources for a home purchase. Actual costs vary by lender, loan type, location, and negotiated seller credits.

This estimates a purchase mortgage's closing costs. A refinance typically runs somewhat lower as a share of the loan (no new title insurance policy is always required, for instance) — see this site's Mortgage Refinance Calculator, which cites a separate 3-6% refinance-specific range from Chase.

• LendingTree — How much are closing costs? Average costs and fees — accessed 2026-08-25

Maximum monthly transportation budget = gross monthly income × 10% Maximum loan payment = that budget − your other monthly car costs Maximum loan amount = present value of that payment over a 4-year (48-month) term at your interest rate Maximum vehicle price = maximum loan amount + your down payment The 20/4/10 rule — 20% down, a loan term of 4 years or less, transportation costs at or under 10% of gross income — a widely cited car-affordability guideline covered by Chase, J.D. Power, and other major auto and financial publishers.

The 48-month loan term is fixed to match the rule itself, not user-adjustable — a longer term would let you "afford" a more expensive car on paper while paying more total interest, defeating the rule's purpose.

• Chase — The 20/4/10 rule for buying a car — accessed 2026-08-25

Cost of buying = down payment + (loan payments made during the comparison period) − estimated resale value at the end Cost of leasing = (monthly lease payment × months compared) + (due-at-signing fee × number of lease signings needed to cover that period) If the comparison period is longer than one lease term, this assumes you re-lease at the same monthly payment and fee each time — real-world lease pricing changes between terms, so treat a multi-lease comparison as a rough estimate, most reliable when the comparison period is close to a single lease term.

• Wikipedia — Vehicle leasing — accessed 2026-08-29

Balance grows monthly as: balance × (1 + monthly return) + monthly contribution, compounded across the number of months until enrollment. 529 plans grow federally tax-free, and withdrawals are also federal-tax-free when used for qualified education expenses (tuition, fees, room and board, and more) — the core reason a 529 is generally favored over a taxable account for this specific goal, per IRS and SEC investor-education guidance.

Contributions to a 529 count as gifts for tax purposes. A single contributor can give up to the annual gift tax exclusion ($19,000 for 2026) per beneficiary without filing a gift tax return, and 529 plans specifically allow "superfunding" — electing to treat a lump sum of up to 5 years' worth of that exclusion ($95,000 single, $190,000 married for 2026) as spread evenly over 5 years for gift-tax purposes. This calculator doesn't model lump-sum superfunding directly — enter an equivalent average monthly contribution instead.

• SEC Office of Investor Education — An Introduction to 529 Plans — accessed 2026-08-25

Sticker price = tuition & fees + room & board + other costs (books, supplies, transportation, personal). Net price = sticker price − expected grant/scholarship aid (floored at $0). Effective discount rate = grant aid ÷ sticker price.

This tool cannot know what grant/scholarship aid any specific school will actually offer you — federal law requires every US college to publish its own Net Price Calculator (usually on its financial aid website), which uses that school's own aid formulas and your actual financial details to give a real, individualized estimate. Use that school-specific tool for a real number, then enter its result as 'expected grant/scholarship aid' here. 'Grant/scholarship aid' means aid you don't repay — it excludes loans, which reduce your net price but don't reduce what you ultimately pay including interest. Preset sticker prices are 2025-26 College Board national averages, not any specific school's actual cost.

• College Board — Trends in College Pricing and Student Aid — accessed 2026-08-30
• U.S. Department of Education — Net Price Calculator requirement — accessed 2026-08-30

Dependent students: Parent Income Protection Allowance (IPA) scales with family size (2026-27 anchor: $44,880 for a family of 4); income above the IPA is assessed on an approximate graduated schedule from 22% up to 47%. Student's own income above a $11,770 allowance is assessed at a flat 50%. SAI = parent contribution + student contribution. Independent students (no dependents): income above an $18,310 allowance is assessed on the same approximate graduated schedule.

This is a rough, income-only approximation — not an official calculation. The real 2026-27 FAFSA Student Aid Index also assesses family assets (savings, investments, and for some filers business/farm net worth) separately from income, uses an official multi-bracket assessment table this tool only approximates with 5 bands, and can even go negative (as low as -1500) for the lowest-income families to help target need-based aid. The FAFSA Simplification Act (2024-25 onward) eliminated the old EFC's 'divide by number in college' step entirely — SAI no longer automatically falls just because more than one sibling is enrolled. File the actual FAFSA at studentaid.gov for your real SAI — no unofficial tool, including this one, can substitute for it.

• Federal Student Aid — 2026-27 Student Aid Index (SAI) and Pell Grant Eligibility Guide — accessed 2026-08-30
• Federal Student Aid — FAFSA Simplification Act overview — accessed 2026-08-30

Total monthly expenses = rent + food + transportation + textbooks/supplies + personal/entertainment + savings. Total monthly income = financial aid disbursement + job income + family support + savings drawdown. Monthly surplus/shortfall = total income − total expenses.

This covers day-to-day living costs only — tuition and fees are assumed to be handled separately (financial aid, loans, or family payment made directly to the school), so only aid actually disbursed to you for living expenses should go in 'financial aid disbursement.' Every field is a monthly average you should adjust to your own real numbers; costs like textbooks are often lumpy (a big expense at the start of a semester) rather than perfectly even month to month.

• Federal Student Aid — Understanding financial aid disbursement — accessed 2026-08-30

The calculator first derives your regular monthly payment from the standard amortizing-loan formula (remaining balance, rate, and remaining term). It then simulates two schedules month by month: the original one at the regular payment, and a second one where your extra amount is added to principal every month, tracking how many months each takes to reach a zero balance and how much total interest each accrues. The difference between the two is what's shown as saved.

This assumes every extra dollar goes straight to principal reduction, applied consistently every month for the life of the loan. Confirm with your servicer that extra payments are actually applied that way by default — some servicers apply an extra payment toward your next due date instead of principal unless you specifically instruct otherwise, which would not produce these savings.

• Consumer Financial Protection Bureau — How can I lower my mortgage payments? — accessed 2026-08-29

Down payment amount = home price × down payment % Loan amount = home price − down payment amount PMI (private mortgage insurance) is typically required by conventional lenders when the down payment is below 20% of the home's value, since a smaller down payment means less equity cushioning the lender's risk if the borrower defaults.

20% is the conventional-loan convention for avoiding PMI, not a universal rule — government-backed programs work differently: FHA loans allow down payments as low as 3.5% (with their own separate mortgage insurance premium that doesn't go away at 20% equity the way conventional PMI can), and VA loans for eligible veterans can allow 0% down with no mortgage insurance at all. This calculator models the conventional-loan 20% convention specifically.

• Consumer Financial Protection Bureau — What is a down payment? — accessed 2026-08-29

Front-end DTI = monthly housing payment ÷ gross monthly income × 100 Back-end DTI = (monthly housing payment + other monthly debt payments) ÷ gross monthly income × 100

These are lender guidelines and conventions, not a single universal legal cap. The Consumer Financial Protection Bureau's General Qualified Mortgage rule used a strict 43% DTI limit until it was formally removed in 2021 and replaced with a price-based (loan pricing) test — so a 43% figure is still widely cited as a rough conventional/FHA reference point, but it is no longer a hard regulatory ceiling for most conventional loans. Actual approval always depends on the specific lender and loan program.

• Consumer Financial Protection Bureau — What is a debt-to-income ratio? — accessed 2026-08-29
• Consumer Financial Protection Bureau — General QM loan definition final rule (removal of the 43% DTI limit) — accessed 2026-08-29

Monthly payment = P × r × (1 + r)^n / ((1 + r)^n − 1), where P is the loan amount, r is the monthly rate (APR ÷ 12 ÷ 100), and n is the term in months. Total interest = (monthly payment × n) − P. Origination fee = loan amount × fee %. Most lenders deduct this from the funds they disburse rather than adding it to your balance — so the amount you actually receive is the loan amount minus the fee, while you still owe and repay the full loan amount plus interest. Total cost = (monthly payment × n) + origination fee.

Origination fees are commonly deducted from the loan proceeds before disbursement (so you receive less cash than the loan amount even though you owe and repay the full amount) — but exact handling varies by lender, so confirm it against your specific loan agreement rather than assuming. Most personal loans also don't carry a prepayment penalty, but a portion of lenders still include one, especially in the first year or two, so check your agreement before counting on paying it off early for free.

• Consumer Financial Protection Bureau — Do personal installment loans have fees? — accessed 2026-08-29
• NerdWallet — Average Personal Loan Interest Rates for August 2026 — accessed 2026-08-29

Equivalent salary needed = current salary × (destination index ÷ current-city index) Cost-of-living difference (%) = (destination index ÷ current-city index − 1) × 100 Purchasing power of an unchanged salary after moving = current salary ÷ (destination index ÷ current-city index)

This calculator has no live cost-of-living database — the two index numbers are entirely user-supplied. A common source is Numbeo's Cost of Living Index, which sets one reference city (Numbeo uses New York City) at 100 and scores every other city relative to it from a weighted basket of prices (rent, groceries, restaurants, transportation, utilities, and more), built from user-submitted price data. Different sources (Numbeo, Mercer, ECA International, government statistical agencies) use different baskets, weights, and reference cities, so the same two cities can carry different index numbers depending on where you look — pick one source and use it consistently for both locations. This tool also doesn't model taxes, currency conversion, or exchange-rate risk for international moves; it's a pure ratio calculation on whatever two numbers you enter.

• Numbeo — Understanding Our Cost of Living Indices — accessed 2026-08-29

Payment = (PV × r) ÷ (1 − (1 + r)^−n), the standard annuity-payment formula, where PV is the lump sum, r is the periodic rate (annual rate ÷ periods per year), and n is the total number of periods (years × periods per year). This fully amortizes the lump sum to exactly $0 by the end of the payout length, factoring in ongoing investment growth on the remaining balance along the way.

This assumes a constant rate of return every period for the entire payout length, which real investment returns never actually deliver — they vary significantly year to year, and a market downturn early in the payout period can be far more damaging than the same downturn later (sequence-of-returns risk), something this simple constant-rate model doesn't capture. It also doesn't account for taxes, fees, or inflation eroding the real value of each fixed payment over a long payout period.

• Investopedia — Amortization: Definition and How It Works, With Examples (annuity-payment formula) — accessed 2026-08-30

Contribution margin per unit = Price per unit − Variable cost per unit Contribution margin % = Contribution margin per unit ÷ Price per unit × 100 Break-even point (units) = Fixed costs ÷ Contribution margin per unit Break-even point (revenue) = Break-even units × Price per unit

This models a single product or service at a constant price and constant variable cost per unit — the standard simplified break-even formula used for business planning. A business selling multiple products with different margins doesn't have one break-even point; each product (or a sales-weighted blended margin across all of them) would need its own calculation. Treat this as a planning estimate, not an accounting result — it doesn't account for taxes, financing costs, or costs that are only partly fixed (semi-variable costs), which should be split into their fixed and variable portions before using this calculator.

• U.S. Small Business Administration — Calculate your break-even point — accessed 2026-08-29

Employee contribution = salary × your contribution % (quoted gross, as landed in the pension under a relief-at-source scheme). Employer contribution = salary × employer %. Basic-rate relief (20%) is added automatically at source and is already included in the gross employee figure above; higher-rate (40%) and additional-rate (45%) taxpayers must separately claim the difference above 20% back via Self Assessment — that extra relief is paid to you, not into your pension. True net cost from your payslip = employee contribution × (1 − your tax band rate). Projected pot = current pot × (1 + growth)^years + annual total contribution × [((1 + growth)^years − 1) ÷ growth].

Uses the 2026/27 UK pension Annual Allowance (£60,000) and standard Income Tax bands. Assumes a relief-at-source workplace scheme (the common default, e.g. NEST) where your contribution is quoted gross and basic-rate relief is added automatically — some employers instead use a 'net pay' arrangement, where all relief (including higher/additional rate) is automatic regardless of band, with no separate claim needed. Doesn't model the Tapered Annual Allowance, the Money Purchase Annual Allowance (£10,000), National Insurance, or salary sacrifice arrangements. Not financial or tax advice.

• GOV.UK — Tax on your private pension: Annual allowance — accessed 2026-08-30
• MoneyHelper — How pension auto-enrolment works — accessed 2026-08-30

Contribution room from income = min(18% × last year's earned income, the year's RRSP dollar limit). Total room = that + any carried-forward unused room from prior years. Contribution applied = min(your planned contribution, total room). Tax refund = contribution applied × your marginal tax rate. Projected balance = current balance × (1 + growth)^years + this contribution × [((1 + growth)^years − 1) ÷ growth], assuming the same contribution repeats annually.

Uses the 2026 RRSP dollar contribution limit ($33,810 CAD). Unused contribution room carries forward indefinitely — there's no 'use it or lose it' deadline the way there is with a TFSA's annual limit reset. Over-contributing by more than a $2,000 lifetime grace buffer can trigger a CRA penalty tax of 1% per month on the excess. Doesn't model the Home Buyers' Plan, Lifelong Learning Plan, pension adjustments from an employer plan, or spousal RRSPs. Not financial or tax advice.

• Canada Retirement Income — RRSP Contribution Limit 2026 — accessed 2026-08-30
• Questrade — RRSP contribution rules and the 18% earned-income calculation — accessed 2026-08-30

SG contribution = salary × SG rate. Total concessional contributions = SG + salary sacrifice, capped at the concessional contributions cap. Contributions tax = capped total × 15%. Net added to super = capped total − contributions tax. Tax saved by salary-sacrificing = salary sacrifice amount × (your marginal rate − 15%). Projected balance = current balance × (1 + growth)^years + net annual contribution × [((1 + growth)^years − 1) ÷ growth].

Uses the FY2026-27 concessional contributions cap ($32,500 AUD) and the standard 15% contributions tax rate. High-income earners (adjusted income over $250,000) pay an additional Division 293 tax of 15% on part of their concessional contributions, not modeled here. Doesn't model non-concessional contributions, the 5-year carry-forward rule, or the SG maximum contribution base. Not financial advice.

• Australian Taxation Office — Concessional contributions cap — accessed 2026-08-30
• AustralianSuper — FY27 Superannuation Changes for Employers — accessed 2026-08-30

Discounted rate = no-points rate − (points purchased × rate reduction per point). Points cost = loan amount × (points purchased ÷ 100). Monthly payment (either rate) = P × r / (1 − (1+r)^−n). Monthly savings = payment at no-points rate − payment at discounted rate. Break-even (months) = points cost ÷ monthly savings.

Each point's rate reduction is set by the lender, not a fixed law — 0.25% per point is a commonly cited average, but it varies by lender, loan program, and rate environment. This tool doesn't model points as tax-deductible or shop real lender quotes. If you'll sell or refinance before the break-even point, buying points is usually not worth it.

• Bankrate — What Are Mortgage Points And How Do They Work? — accessed 2026-08-30

Monthly payment = P × r / (1 − (1+r)^−n), computed for the fixed loan over the full term, and separately for the ARM's initial period. Remaining balance at the adjustment date = P×(1+r)^k − M×((1+r)^k−1)/r, where k is the number of payments made in the initial period. The ARM's post-adjustment payment re-amortizes that remaining balance at your assumed adjusted rate. Total interest = total of all payments − original principal.

Real ARMs cap how much the rate can move using a structure commonly written as e.g. 2/2/5: at most a 2-point change at the first adjustment, at most 2 points at any later adjustment, and at most 5 points above the initial rate over the life of the loan. This tool uses one assumed post-adjustment rate for the entire remaining term rather than simulating every future adjustment individually. Most conforming ARMs now adjust every 6 months after the initial fixed period (hence '5/6' rather than the older '5/1' naming).

• Consumer Financial Protection Bureau — What are rate caps with an ARM? — accessed 2026-08-30
• Chase — Mortgage ARM Caps: What To Know — accessed 2026-08-30
• Rocket Mortgage — 5/1 vs. 7/6 vs. 10/6 adjustable-rate loans — accessed 2026-09-01

Nights booked per month = occupancy % × 30.44. Gross booking revenue = nightly rate × nights booked. Airbnb host fee = gross revenue × host fee %. Property management fee (if any) = gross revenue × management fee %. Net short-term profit = gross revenue − host fee − management fee − fixed monthly costs. Net long-term profit = long-term rent − fixed monthly costs.

Airbnb consolidated its old split guest/host fee model into a single host-only service fee — 15.5% in most markets, 16% in Brazil and Mexico — rolled out through September/October 2026; check your own host dashboard for your account's current rate. This tool assumes cleaning fees are a pass-through with roughly zero net effect, and does not include vacancy ramp-up time, furnishing/setup costs, STR permits or licensing fees, additional insurance, or local occupancy/lodging taxes. Short-term rentals are restricted or banned outright in some cities and HOAs — confirm local legality first. Not financial or tax advice.

• Hostaway — Airbnb Host-Only Fee Explained — accessed 2026-08-30
• Lodgify — Airbnb Hosting Fees: What Percentage Does Airbnb Take in 2026? — accessed 2026-08-30

Dividend yield = Annual dividend per share ÷ Current share price × 100. DRIP projection: each year, income = shares held × that year's dividend per share (grown at your assumed rate); that income buys income ÷ that year's share price (grown at your assumed rate) additional shares, added to the share count for the following year.

The DRIP projection assumes dividend and price growth rates stay constant every year, which real markets never do exactly. Treat it as a directional planning tool, not a forecast. It also ignores taxes on reinvested dividends, which are typically still taxable in the year received even though you never receive the cash.

• Investor.gov (U.S. SEC) — Dividends and dividend reinvestment plans explained — accessed 2026-08-30

FIRE number = Annual expenses ÷ Withdrawal rate (e.g. at 4%, FIRE number = 25 × annual expenses). Projected savings after n years = current savings × (1+r)^n + annual contributions × (((1+r)^n − 1) ÷ r), solved iteratively year-by-year (capped at 60 years) to find the first year the projection meets or exceeds the FIRE number.

Assumes a constant annual return every year, which real investment returns never actually deliver. Ignores taxes, inflation eroding future expenses, and other income sources like Social Security. The withdrawal rate is a widely used planning heuristic from historical U.S. market backtests, not a mathematical guarantee.

• Investopedia — The 4% Rule: What It Is and How It Works for Retirement — accessed 2026-08-30

Future value = Present value × (1 + r)^n. Present value = Future value ÷ (1 + r)^n, where r is the rate per period (as a decimal) and n is the number of periods.

This models a single lump sum only — it doesn't include recurring contributions or withdrawals. The rate and number of periods must use consistent units: mixing an annual rate with a monthly period count will give a meaningless answer.

• Corporate Finance Institute — Present Value (PV) and Future Value (FV) formulas explained — accessed 2026-08-30

NPV = −Initial investment + Σ [Cash flow_t ÷ (1 + rate)^t], summed over each future period t.

Assumes regular, equal-length periods and a single, constant discount rate across the whole horizon. Doesn't do irregular-date discounting (XNPV) or model a term structure of rates that varies by year.

• Corporate Finance Institute — Net Present Value (NPV) formula and capital budgeting overview — accessed 2026-08-30

IRR is the rate r that solves: 0 = −Initial investment + Σ [Cash flow_t ÷ (1 + r)^t]. Solved iteratively via Newton-Raphson from a 10% starting guess, falling back to a bounded bisection search between −99% and +1,000% if Newton-Raphson fails to converge.

For a typical project — one upfront outflow followed only by inflows — there's a single well-defined IRR. If cash flows change sign more than once, more than one mathematically valid IRR can exist; this tool reports the root nearest its starting guess and flags multiple sign changes explicitly. IRR also implicitly assumes interim cash flows are reinvested at the IRR itself.

• Investopedia — Internal Rate of Return (IRR): Formula and Examples — accessed 2026-08-30

Monthly payment = P × r × (1+r)^n ÷ [(1+r)^n − 1], where P is the loan amount, r is the monthly interest rate (APR ÷ 12 ÷ 100), and n is the number of monthly payments. Total interest = (monthly payment × n) − P.

Assumes a fixed-rate, fully-amortizing loan for every offer — no balloon payment, no variable-rate adjustment, and no origination fees or points factored in. If any offer carries fees the others don't, factor those in separately.

• Consumer Financial Protection Bureau — Understanding loan terms and comparing loan offers — accessed 2026-08-30

Net profit needed = desired take-home ÷ (1 − 14.1296%), where 14.1296% = 92.35% (Schedule SE factor) × 15.3% (combined self-employment tax rate). Self-employment tax = net profit needed − desired take-home. Required revenue = net profit needed + annual business expenses. Available hours = (52 − weeks off) × hours per week. Billable hours = available hours × billable %. Hourly rate = required revenue ÷ billable hours.

Grosses up only for the 15.3% self-employment tax — federal and state income tax are not included, so the take-home figure is pre-income-tax. The formula is linear and exact only while net profit stays under the 2026 Social Security wage base (~$199,784); above that it slightly overstates the required rate. The 50-70% billable-hours range commonly cited for solo freelancers is an industry rule of thumb, not a guarantee.

• IRS — Self-Employment Tax (Social Security and Medicare Taxes) — accessed 2026-08-30

Local moves are priced as a flat range by home size (2-person crew + truck, hourly-rate-based). Long-distance moves are priced by home size × a distance band, since real long-distance quotes are driven by shipment weight and distance together, not a flat per-mile rate.

These are industry-average ranges for a standard full-service move, not a quote. Actual cost varies by season, the specific moving company, real weight of belongings, and access difficulty. Packing services, specialty items, storage-in-transit, and tips aren't included.

• Angi — How Much Does It Cost to Hire Movers? — accessed 2026-08-30

Each category's suggested amount = total budget × that category's allocation percentage (12 categories summing to 100%: Catering & bar 25%, Venue & rentals 17%, Photography & video 11%, Flowers & decor 9%, Music & entertainment 8%, Attire & beauty 8%, Planner/coordinator 6%, Contingency buffer 4%, Rings 4%, Stationery & invites 3%, Transportation 3%, Favors & gifts 2%).

These percentages are a planning heuristic from The Knot's 2026 Real Weddings Study, not a rule — actual spend varies enormously by region, guest count, and personal priorities.

• The Knot — 2026 Real Weddings Study — accessed 2026-08-30

Net burn = monthly expenses − monthly revenue (floored at 0). Runway (months) = current cash balance ÷ net burn. Projected cash-out date = today + (runway months × ~30.44 average days/month).

This assumes cash balance, monthly expenses, and monthly revenue all stay constant going forward — real startups' spending and revenue fluctuate, so treat the result as a snapshot based on today's numbers, not a guaranteed forecast.

• a16z — What is startup runway, and how should founders think about it — accessed 2026-08-30

CAC = sales & marketing spend ÷ new customers acquired. Customer lifespan (years) = either your direct estimate, or 100 ÷ annual churn rate (%). LTV = average purchase value × purchase frequency (per year) × customer lifespan (years). LTV:CAC ratio = LTV ÷ CAC.

This uses the simple revenue-based LTV formula, not a margin-adjusted or discounted-cash-flow LTV — real gross margin and discount rates aren't modeled, so treat the result as directional. The commonly-cited '3:1 or better' health benchmark comes from SaaS/VC circles, based on observing mature subscription businesses — a widely-used rule of thumb, not a universal law.

• ChartMogul — CAC and LTV: how to calculate and interpret SaaS unit economics — accessed 2026-08-30

MRR = active subscribers × ARPU. ARR = MRR × 12. Projection (per month, for 12 months): next month's MRR = this month's MRR − (this month's MRR × churn rate) + new MRR added.

The 12-month projection applies one blended monthly churn rate against the entire MRR balance, plus a flat new-MRR add each month — a simplified stand-in for the fuller 'new + expansion − contraction − churned' cohort model. MRR and ARR count only recurring subscription revenue, excluding one-time fees, by standard SaaS-metrics convention — and ARR here is simply MRR × 12, not a literal annual-contract-value figure.

• Stripe — MRR and ARR: definitions, formulas, and why they matter for SaaS — accessed 2026-08-30

Percentage method: the first $1,000,000 of a calendar year's cumulative supplemental wages is withheld at a flat 22%; any amount above that is withheld at 37%. Aggregate method (IRS Publication 15-T's annualized-wages approach): your regular per-period wages are annualized to find the tax on that alone; the bonus is added to that period's pay and the combined amount is annualized the same way; the difference between the two annualized tax figures, divided back by the number of pay periods, is the withholding attributable to the bonus.

Both methods are legitimate, IRS-permitted ways an employer can withhold federal income tax on a bonus — which one applies is the employer's choice, not yours. Neither number is your final tax bill: withholding is only a prepayment, reconciled against your actual full-year tax liability when you file (see the W-4 Withholding Calculator). This tool covers federal income tax withholding only — FICA is still withheld on a bonus at normal rates, and state/local withholding isn't modeled. Not tax advice.

• IRS Publication 15 (Circular E) — Employer's Tax Guide — accessed 2026-08-30
• IRS — Publication 15-T, Federal Income Tax Withholding Methods — accessed 2026-08-30

W-2 take-home (pre-income-tax) = salary − employee FICA (6.2% Social Security up to the wage base + 1.45% Medicare). W-2 employer's total cost = salary + benefits value + employer's own matching FICA share. 1099 net profit = (hourly rate × billable hours) − business expenses. 1099 self-employment tax = 92.35% of net profit × 15.3%. 1099 take-home (pre-income-tax) = net profit − self-employment tax.

Both take-home figures are shown before federal/state income tax, which both paths owe on broadly similar brackets — the real difference isolated here is payroll tax, benefits, and deductible business expenses, not income tax itself. This tool does not determine whether a role is legally a W-2 employee or a 1099 contractor — that's governed by IRS common-law, DOL economic-reality, and (in some states) ABC-test rules. Not legal or tax advice.

• IRS — Self-Employed Individuals Tax Center — accessed 2026-08-30
• U.S. Department of Labor — Employee or Independent Contractor Classification Under the FLSA — accessed 2026-08-30

Taxable income = gross wages + other income − standard deduction (2026: $16,100 single/MFS, $32,200 MFJ, $24,150 HoH) − extra deductions. Tax before credits = 2026 federal bracket schedule for your filing status. Child Tax Credit + Credit for Other Dependents = ($2,200 × qualifying children) + ($500 × other dependents), reduced by $50 per $1,000 over $200,000 (single/HoH) or $400,000 (MFJ). Estimated tax liability = tax before credits − total credit (floored at $0). Estimated refund/owed = expected withholding − estimated tax liability.

This estimates income tax liability and reconciles it against expected withholding — it does not walk through the IRS Form W-4's own worksheet lines the way the IRS's own Tax Withholding Estimator does. It doesn't include FICA, state/local income tax, self-employment income, or other credits. A large refund means you had more withheld than necessary all year — an interest-free loan to the government, not a bonus. Not tax advice.

• IRS — Tax inflation adjustments for tax year 2026 (Rev. Proc. 2025-32) — accessed 2026-08-30
• Kiplinger — Child Tax Credit 2026: Amount, Income Limits, and What's Changed — accessed 2026-08-30

Personal Allowance = £12,570, reduced £1 for every £2 of income above £100,000, fully gone at £125,140. Income Tax: 20% on taxable income up to £37,700 above the allowance (up to £50,270 total income), 40% on the next £74,870 (up to £125,140), 45% above. Class 1 employee National Insurance: 0% up to £12,570, 8% between £12,570 and £50,270, 2% above £50,270. Take-home pay = income − Income Tax − National Insurance.

Covers England, Wales & Northern Ireland rates only — Scotland sets its own Income Tax bands, not modeled here. Assumes a standard tax code, one employment, and no salary sacrifice, pension contributions, or student loan deductions. Not tax advice.

• GOV.UK — Income Tax rates and Personal Allowances — accessed 2026-08-30
• GOV.UK — National Insurance rates and categories — accessed 2026-08-30

Gross federal tax is computed progressively across 5 brackets (14% to $58,523, 20.5% to $117,045, 26% to $181,440, 29% to $258,482, 33% above). The Basic Personal Amount (BPA, $16,452 for income up to $181,440, tapering to $14,829 by $258,482) is converted into a non-refundable tax credit worth BPA × 14% and subtracted from gross tax.

Models federal tax only. Every Canadian province and territory levies its own additional income tax with its own brackets — your real total tax bill will be higher. Also excludes CPP/EI premium deductions and other credits. Not tax advice.

• Canada.ca — Canadian income tax rates for individuals — accessed 2026-08-30
• Canada.ca — Current year tax rates and income brackets for individuals — accessed 2026-08-30

Income tax is computed progressively across 5 brackets: 0% up to $18,200, 15% up to $45,000, 30% up to $135,000, 37% up to $190,000, 45% above. The Medicare levy is a flat 2% of taxable income, phased in between roughly $28,011 and $35,013 for low-income earners. Take-home pay = income − income tax − Medicare levy.

Uses 2026-27 resident tax brackets, including the 16%→15% second-bracket cut effective 1 July 2026. Assumes Australian tax residency and doesn't model HECS/HELP repayments, the Medicare Levy Surcharge, or the Low Income Tax Offset. Not tax advice.

• Superguide — Australian income tax brackets and rates — accessed 2026-08-30
• Wage Calculator — ATO Tax Rates 2026-27 — accessed 2026-08-30

Estimated premium = national-average base premium (by coverage level) × age multiplier × state-cost-tier multiplier × vehicle-type multiplier × driving-record multiplier.

This is a directional, illustrative estimate built from national averages and a handful of broad adjustment factors — not a real quote. Real premiums come from an insurer's underwriting of your specific driving history, exact vehicle (VIN-level), credit-based insurance score (used in most states, though California, Hawaii, and Massachusetts ban the practice), annual mileage, and marital status. The vehicle-type multipliers are directional only — no single authoritative national table breaks down premiums by vehicle category — and the state figure is a broad cost tier anchored to the cheapest and most expensive states on average, not a lookup for your specific state.

• NerdWallet — How Much Is Car Insurance in 2026? — accessed 2026-08-30

First-year total = childcare + feeding + diapers & wipes + medical (out-of-pocket) + gear & nursery (one-time) + clothing & misc — each entered or selected independently, then simply summed.

Childcare is by far the largest and most variable category (ranging from $0 for stay-at-home/family care to $21,000+ for a nanny in a high-cost metro), so it's broken out as its own selector rather than baked into one blended average. All figures are US-centric annual (or one-time, for gear) estimates and will vary significantly by location and individual circumstances.

• BabyCenter — The cost of raising a baby in the first year — accessed 2026-08-30

Fuel cost = (annual miles ÷ mpg) × gas price per gallon. Maintenance cost = annual miles × maintenance cost per mile. Total annual cost = depreciation + insurance + fuel + maintenance + registration. Cost per mile = total annual cost ÷ annual miles.

Depreciation, insurance, maintenance, and registration defaults are national-average figures derived from AAA's annual 'Your Driving Costs' study, scaled toward a small/mid-size sedan — AAA publishes a full cost breakdown only for its fleet-wide average across 9 vehicle categories, so the sedan-level split is a proportional estimate (about 72% of the fleet-average dollar figures), not a verbatim AAA-published sedan table. Fuel is the one line recalculated live from your own mpg and gas-price inputs, using today's live national average gas price rather than AAA's own (already outdated) study assumption. This tool doesn't include your loan payment — pair it with the Auto Loan Calculator for principal and interest.

• AAA — Your Driving Costs (annual national-average vehicle ownership cost study) — accessed 2026-08-30

Each month: interest = balance × (APR ÷ 12 ÷ 100). Minimum payment = max(flat-dollar floor, balance × minimum % + that month's interest). New balance = balance + interest − payment. The simulation repeats month by month until the balance reaches zero (or is capped at 50 years, flagging a payment that never actually pays down the balance).

Minimum-payment formulas vary by issuer — this models the common 'percent of balance plus that month's interest, or a flat-dollar floor, whichever is greater' structure, but check your own card's actual terms. Because most minimum payments shrink as the balance shrinks (a smaller % of a smaller balance), paying only the minimum can take many years and cost more in interest than the original balance itself — this simulation makes that visible month by month rather than with a single simplified formula.

• Consumer Financial Protection Bureau — How credit card minimum payments are calculated — accessed 2026-08-30

Each action's effect = its FICO category weight (payment history 35%, amounts owed 30%, length of history 15%, new credit 10%, credit mix 10%) × a simplified swing budget (150 points) × a magnitude reflecting how large that specific action is (e.g. how much utilization changed, how long the on-time streak is). All effects are added directionally to the starting score, clamped to the 300-850 FICO range.

This is not a real FICO or VantageScore calculation — the actual proprietary algorithm evaluates your entire credit file together and cannot be reproduced by any outside tool, including this one. This simulator applies simple, capped directional adjustments based on FICO's own published category weights purely to illustrate which way, and roughly how much, common actions tend to move a score. The CFPB has noted that an educational score can differ meaningfully from the score a lender actually uses for roughly 1 in 4 consumers. Never use this to predict, guarantee, or substitute for your real credit score — check your card issuer's free score, myFICO, or an official credit bureau for that.

• myFICO — What's in my FICO Scores? (published category weights) — accessed 2026-08-30
• Consumer Financial Protection Bureau — Credit scores used by lenders can differ from educational scores — accessed 2026-08-30

For each period i (0-indexed): price = starting price × (1 + trend)^i. Units bought that period = investment amount ÷ that period's price. Total units = sum of all periods' units. Total invested = investment amount × number of periods. Average cost per unit = total invested ÷ total units. Ending value = total units × the final period's price.

This has no live or historical crypto price feed — prices are entirely generated from a starting price and a constant assumed trend rate you supply, not real market data. Dollar-cost averaging does not guarantee a profit or protect against loss in a declining market, and crypto assets are highly volatile and speculative. Treat every result here as a 'what if prices moved this way' illustration of DCA mechanics, not a forecast, backtest, or investment recommendation.

• Investopedia — Dollar-Cost Averaging (DCA) Explained With Examples and Considerations — accessed 2026-08-30

Order total = sale price + shipping charged to buyer. Referral/transaction fee = order total × referral %. Payment processing fee = order total × payment % + payment fixed fee. Total fees = referral fee + fixed per-order fee + payment processing fee. Net profit = order total − cost of goods sold − seller-paid shipping − total fees. Profit margin = net profit ÷ order total.

The preset values are real, currently-published rates for one representative case each — Amazon's 15% referral fee is the general-category rate (actual range is 5%-45% by product category) with the Individual-plan $0.99/item fee (a Professional plan charges $39.99/month flat instead); Etsy's 6.5% transaction fee plus 3%+$0.25 payment processing (US) and a $0.20 listing fee. Fee structures vary by platform, product category, seller plan, and processor, and change over time — verify current rates on your actual platform before relying on this for pricing or business decisions.

• Amazon Seller Central — Selling on Amazon fee schedule — accessed 2026-08-30
• Etsy — Fees and payments policy — accessed 2026-08-30

Energy needed (kWh) = battery capacity × (target charge % − current charge %) ÷ 100. Cost = energy needed × price per kWh (home or public rate, as selected).

This computes energy delivered to the battery (the state-of-charge change you enter), not wall-metered draw — it doesn't include AC-to-battery conversion losses (typically 10-15%) or any network session/idle fees some public charging networks charge. The public rate is a single blended estimate, not a live network price — DC fast-charging rates commonly range from about 45¢ to 55¢/kWh depending on the network, region, and membership tier; some plans and Level 2 public charging run considerably cheaper.

• U.S. Energy Information Administration — Average residential electricity rates by state — accessed 2026-08-30

Gas annual operating cost = (miles ÷ mpg × gas price/gal) + (miles × gas maintenance $/mile). EV annual operating cost = (miles × kWh/100mi ÷ 100 × price/kWh) + (miles × EV maintenance $/mile). Total cost (each) = purchase price + annual operating cost × holding years. Breakeven (years) = (EV purchase price − gas purchase price) ÷ (gas annual operating cost − EV annual operating cost), when the EV costs more upfront but less to run.

Maintenance cost defaults reflect Consumer Reports' lifetime-average $/mile figures (2020 study) for gas vs. electric vehicles — EVs generally have fewer moving parts (no oil changes, fewer brake replacements due to regenerative braking) and correspondingly lower typical maintenance costs, though this varies by specific vehicle and usage. This doesn't include financing costs (loan interest), insurance differences, potential tax credits/rebates for EV purchases, or resale value differences between the two vehicle types at the end of the holding period.

• Consumer Reports — Electric Vehicles Offer Big Savings Over Time (maintenance cost data) — accessed 2026-08-30

For each year between the starting year and the target year, the calculator multiplies by (1 + that year's annual CPI-U inflation rate) if moving forward in time, or divides by the same chained factor if moving backward (e.g. "what would today's $X have been worth in 2005"). The cumulative factor across all intervening years converts the amount; cumulative % change = (factor − 1) × 100; annualized rate = (factor^(1/number of years) − 1) × 100. Years outside the 2005–2025 table use a flat assumed annual rate you can adjust, instead of a sourced historical figure.

This uses a static, sourced table of historical US CPI-U annual average inflation rates covering 2005–2025 — not a live feed from the Bureau of Labor Statistics. A browser-side tool has no practical way to authenticate against and rate-limit-manage the BLS API on every calculation, so the table is baked in with a defined cutoff year (2025). Any year requested outside that window — earlier history or a future projection — falls back to a plain assumed average annual rate that you control, clearly distinct from the sourced 2005–2025 figures. This is a purchasing-power re-pricing tool, not a wage-growth, investment-return, or economic-forecasting tool.

• U.S. Inflation Rates by Year: Historical Data (BLS CPI-U annual averages) — accessed 2026-08-29

Contribution limit = the IRS limit for your account type and coverage (HSA: self-only or family, plus a $1,000 catch-up if you're 55+ and not on Medicare) or the flat Health FSA limit. Effective contribution = min(your planned contribution, that limit). Combined tax rate = your marginal income-tax rate, plus 7.65% FICA if the contribution is payroll-deducted. Tax savings = effective contribution × combined rate. Net cost of this year's expenses = expected expenses − (expenses actually covered by the contribution × combined rate). Any contribution beyond this year's expenses rolls over indefinitely for an HSA, or is normally forfeited at year-end for an FSA (unless your employer offers a limited carryover or grace period).

Figures reflect the 2026 tax year IRS limits (HSA: Rev. Proc. 2025-19; FSA: Rev. Proc. 2025-32, both confirmed via IRS.gov). This tool uses a simplified combined marginal-rate calculation — it does not model state income tax (which varies, and some states, including California and New Jersey, tax HSA contributions), phase-outs, itemization interactions, or your plan's specific carryover/grace-period rules. An HSA also requires enrollment in an IRS-qualifying High-Deductible Health Plan (HDHP) — contributing to one without qualifying HDHP coverage can trigger tax penalties. An FSA's unused balance is normally forfeited at year-end ('use it or lose it') unless your employer opts into a limited carryover (2026 max $680) or a grace period — never both. Treat all output as a planning estimate, not a tax filing calculation.

• Fidelity — HSA contribution limits and eligibility rules for 2026 and 2027 — accessed 2026-08-29
• IRS Newsroom — IRS releases tax inflation adjustments for tax year 2026 (confirms $3,400 Health FSA limit / $680 max carryover) — accessed 2026-08-29
• IRS Rev. Proc. 2025-19 (2026 HSA/HDHP inflation-adjusted amounts, primary source; figures cross-confirmed via Fidelity, KPMG, PSCA secondary reporting since this PDF's text could not be parsed by the fetch tool this session) — accessed 2026-08-29

Gross monthly income = gross annual income ÷ 12 Max rent (30% rule) = gross monthly income × 0.30 Max rent (3x rule) = gross monthly income ÷ 3 Income needed for a given rent (30% rule) = rent ÷ 0.30 Income needed for a given rent (3x rule) = rent × 3 The two conventions are related but not identical: 30% of income = rent implies income ≈ rent × 3.33 (slightly more conservative), while the 3x-rent convention implies rent ≈ 33.3% of income (slightly less conservative).

These are two widely cited rules of thumb, not individualized underwriting or a legal requirement. The 30% figure traces to the 1969 Brooke Amendment, a federal public-housing law that capped tenant rent contributions (originally 25%, raised to 30% in 1981) — it later became the general benchmark researchers use for 'cost-burdened' housing status, not a private-market rule. The 3x-rent figure is a separate, private-market landlord/property-manager screening convention with no government origin. Both use gross (pre-tax) income. Neither accounts for your actual debt, dependents, savings, or the specific landlord's criteria — some landlords use 2.5x or 4x+ instead of 3x, and alternatives like a guarantor or larger deposit can qualify you even outside these thresholds.

• Wikipedia — Brooke Amendment (1969 public-housing rent cap, raised 25%→30% in 1981) — accessed 2026-08-29
• American Apartment Owners Association — Rent-to-Income Ratio: 30% Rule and 3x Rent explained — accessed 2026-08-29

Cost basis = (buy price × quantity) + buy-side fee, where buy-side fee = (buy price × quantity) × buy fee %. Net proceeds = (sell price × quantity) − sell-side fee, where sell-side fee = (sell price × quantity) × sell fee %. Profit/loss = net proceeds − cost basis. Return % = profit ÷ cost basis × 100.

This calculates a single realized trade only — a full-position close where buy quantity equals sell quantity. It doesn't track cost-basis lots across multiple partial buys/sells (real portfolios often use FIFO, LIFO, or specific-lot identification, which can each produce a different taxable gain from the same trades), doesn't compute any tax owed (short- vs. long-term capital gains treatment varies by country and holding period), and has no live price feed. Not tax or financial advice.

• IRS — Digital Assets (crypto capital gains/loss tax treatment overview) — accessed 2026-08-30

Per-period rate = APY ÷ compounding periods per year. Ending balance = staked amount × (1 + per-period rate)^(compounding periods per year × years). Total rewards = ending balance − staked amount.

This is a hypothetical projection using a constant assumed APY — real staking APY fluctuates with network-wide participation, protocol issuance schedules, and validator/pool performance, and is not fixed or guaranteed. It also doesn't model slashing risk (a penalty reducing your staked principal for a misbehaving or offline validator on some networks), lock-up/unbonding periods that can delay withdrawing your stake for days or weeks, or taxes (many jurisdictions tax staking rewards as ordinary income when received, separate from any later capital gain/loss on the asset itself). Not financial advice.

• Investopedia — What Is Staking in Crypto and How Does It Work? — accessed 2026-08-30

Your share of network = your hash rate ÷ network hash rate. Gross BTC mined per day = your share × 144 blocks/day (24h ÷ 10-minute average block time) × 3.125 BTC current block reward. Net BTC per day = gross BTC × (1 − pool fee %). Revenue per day = net BTC × BTC price. Electricity cost per day = (power watts ÷ 1000) × 24 hours × $/kWh. Profit per day = revenue − electricity cost.

The block reward (3.125 BTC) was set at the April 2024 halving and stays fixed until the next halving, expected around 2028, when it drops to 1.5625 BTC. This tool has no live BTC price or network-hash-rate feed — both change constantly, so enter current figures from a source like blockchain.com or your mining pool's dashboard. It doesn't include hardware purchase cost or depreciation, cooling/hosting fees, or the roughly-every-2-weeks mining difficulty adjustment, which changes the effective network hash rate you should assume going forward. Real-world profitability is frequently thin or negative once all costs are included — this is a directional estimate, not investment advice.

• Braiins — Bitcoin Mining Profitability Calculator methodology and block reward schedule — accessed 2026-08-30
• CoinGecko — Bitcoin Halving Countdown & History — accessed 2026-09-01

Employee FICA = gross × 7.65% (6.2% Social Security + 1.45% Medicare). Withholding = gross × your entered %. Net pay = gross − employee FICA − withholding. Employer FICA match = gross × 7.65%. FUTA = min(gross, $7,000) × 0.6%. SUTA = min(gross, your state's wage base) × your state's rate. Total employer cost = gross + employer FICA match + FUTA + SUTA.

FUTA's 0.6% rate and $7,000 wage base are federal constants (the 0.6% already assumes the standard 5.4% state-unemployment-tax credit most employers qualify for). SUTA's rate and wage base are set by your specific state and your own layoff/claims history (experience rating) — the defaults here are illustrative, not your actual state's figures. Doesn't model workers' comp insurance, benefits costs, or the 0.9% Additional Medicare Tax that applies above $200,000. Not tax advice.

• IRS — Topic no. 759, Form 940 – Employer's Annual Federal Unemployment (FUTA) Tax Return — accessed 2026-08-30

Interest = invoice amount × annual rate × (days overdue ÷ 365) — simple interest, not compounded.

18%/year (1.5%/month) is a widely cited default in US invoice templates, not a legal requirement — late-payment interest is only actually owed if your contract or invoice terms explicitly state a rate. Some US states cap contract interest rates (usury laws) below what you might set here. Check your own contract language and state law before charging a client late fees. Not legal advice.

• FreshBooks — Late Payment Fees: How to Charge Interest on Overdue Invoices — accessed 2026-08-30

Base quote = estimated hours × hourly rate. Buffer = base quote × contingency %. Quote (with buffer) = base quote + buffer. Implied hourly rate from a flat fee = flat fee ÷ estimated hours.

A flat project fee shifts scope-creep risk onto the freelancer — if the project runs over the estimated hours, the effective hourly rate drops. An hourly-plus-buffer quote shifts that risk toward the client instead. The contingency buffer here is a flat percentage, not a project-specific risk assessment — increase it for less-certain scopes.

• Ignition — How to Price and Quote Freelance Projects — accessed 2026-08-30

Payments remaining = 120 − qualifying payments made. Progress % = (payments made ÷ 120) × 100. Estimated forgiveness date = today + payments remaining, in months.

This assumes every payment counted so far was, and every remaining payment will be, a genuine qualifying payment — made under a qualifying repayment plan (an income-driven repayment plan, or the 10-year Standard plan) on Direct Loans, while working full-time for a qualifying employer (government or a 501(c)(3) nonprofit). A gap in full-time qualifying employment, a non-qualifying repayment plan, or a non-Direct loan type can mean a payment doesn't actually count. The only authoritative count is your official PSLF tracker on studentaid.gov via the PSLF Help Tool and employer certification. Not financial or legal advice.

• Federal Student Aid — Public Service Loan Forgiveness (PSLF) — accessed 2026-08-30

Monthly payment is computed from the loan amount and stated rate (standard amortization). The amount you actually receive nets the loan amount against total fees (points % × loan amount, plus any flat fee). True APR is the periodic rate that discounts that same monthly payment stream back to exactly the net amount received, solved numerically (bisection search) and expressed as a nominal annual rate (periodic rate × 12) — the same convention U.S. Truth in Lending Act disclosures use.

This computes a nominal APR (periodic rate × 12), matching Regulation Z's disclosure convention — not an effective/compounded annual rate, which would be slightly higher. The gap between stated rate and APR shrinks the longer the loan term, since the same upfront fee spreads over more payments. This doesn't model a variable-rate loan, mortgage insurance, or fees some official APR disclosures exclude (like a one-time appraisal fee). Not financial advice.

• Consumer Financial Protection Bureau — What is the difference between a mortgage interest rate and an APR? — accessed 2026-08-30

Each year: employee contribution = that year's salary × contribution % (capped at the 2026 IRS limit, $24,500). Employer contribution = that year's salary × min(contribution %, match cap %) × match rate. Balance = prior balance × (1 + return %) + employee + employer contributions. Salary for the next year = this year's salary × (1 + raise %).

Applies the 2026 IRS employee elective-deferral limit ($24,500) to every projected year without inflating that limit forward — the real limit is adjusted for inflation most years, so this likely slightly understates how much you could contribute in later years as your salary (and the cap) both rise. Assumes a constant annual investment return every year, which real markets never deliver, ignores taxes, and doesn't model the age-50+ (or age 60-63 'enhanced') catch-up contribution limits. A planning estimate, not financial advice.

• IRS — 401(k) limit increases to $24,500 for 2026 — accessed 2026-08-30

Increase amount = current rent × (% ÷ 100), or the flat dollar amount entered directly. New rent = current rent + increase amount. Annual added cost = increase amount × 12.

Whether a landlord can raise rent by this amount, and how much notice they must give, depends entirely on local jurisdiction — some cities/states have rent-control ordinances or increase caps, and notice periods (commonly 30-90 days) vary by location and increase size. This tool only computes the math of an increase you enter; it doesn't check any specific law. Not legal advice.

• Investopedia — Rent Control: Definition and How It Works — accessed 2026-08-30

Projected value after n years = starting value × (1 + annual rate)^n. Total gain = projected value − starting value.

Compounds annually at a single assumed rate. Real home values don't move in a smooth line — they rise and fall with local supply/demand, interest rates, and the economy, sometimes declining for multiple years (as in 2008-2012). The FHFA House Price Index shows US home prices appreciating roughly 4% per year nominally on average from 1975-2025, with most long-run national estimates falling in a 3-5% range — any specific neighborhood or period can run well above or below that. About 1-2 percentage points of that long-run average reflects general inflation, not real gain. Not a valuation of your specific property.

• FHFA — House Price Index FAQs and long-run appreciation data — accessed 2026-08-30

Monthly management fee = rent × fee %. Annual management fee = monthly fee × 12. Leasing fee (if placing a new tenant) = rent × leasing fee %. Total first-year cost = annual management fee + leasing fee (if applicable).

Property management fees typically run 8-12% of collected monthly rent nationally, with about 10% the most commonly cited industry benchmark — varies by market, property type, and service scope. A separate one-time leasing/tenant-placement fee (commonly 50-100% of one month's rent) usually applies each time a manager places a new tenant, covering marketing, showings, and screening — it typically doesn't recur for a renewing tenant. Some managers also charge a smaller lease-renewal fee ($100-$500 flat, or 25-50% of a month's rent) and maintenance markups (10-25%) on repair work, neither included here — ask any manager you're evaluating for their full fee schedule. Not financial advice.

• DoorLoop — Property Management Fees by State (2026) — accessed 2026-08-30

Post-money valuation = pre-money + investment. Price per share = pre-money ÷ shares outstanding. New shares issued = investment ÷ price per share. New ownership % = old ownership % × (pre-money ÷ post-money) — every existing holder dilutes by this same ratio regardless of how many shares they hold, since new shares are issued at one shared price for the whole round.

This models a single, simple priced round only. It doesn't account for an option pool top-up (commonly created or expanded right before a round, which dilutes existing holders further than this alone shows), convertible notes/SAFEs converting at the same close, or multiple share classes with different rights/preferences. Not legal or investment advice — a real cap table needs a lawyer or dedicated cap-table tool for anything binding.

• Carta — How startup equity dilution works — accessed 2026-08-30

Gross profit per order = average order value × gross margin %. Total gross profit per customer = gross profit per order × expected purchases. Max break-even ad spend = total gross profit per customer — spend up to this and the acquisition breaks even; spend more and it's a net loss even though revenue may still exceed spend.

This is a simple ratio calculator, not a bidding strategy or attribution recommendation. Counting more than 1 purchase per customer assumes those repeat purchases actually happen at the margin/value entered — a real, not guaranteed, assumption. Doesn't include fixed costs, returns/refunds, platform fees beyond gross margin, or the time value of profit realized over multiple future purchases rather than immediately.

• WordStream — What Is ROAS & How Do I Calculate It? — accessed 2026-08-30

Estimated value = average monthly net profit × valuation multiple. The low/high range shown (25x and 50x) brackets the commonly cited range regardless of your chosen multiple.

This is a rough industry rule of thumb, not an appraisal. Real multiples vary substantially based on revenue trend (growing vs. declining), concentration risk (one customer, one keyword, one traffic source, one platform), owner-dependence (does it run without the current owner's daily involvement), age/stability of the profit history, and business model (SaaS commonly commands a premium over a content or affiliate site). Most marketplaces also expect at least 12 months of consistent profit history before valuing a business by this method at all. Not a substitute for a real broker valuation or professional appraisal.

• Flippa — How to Value a Website — accessed 2026-08-30
• Empire Flippers — Valuation Tool methodology — accessed 2026-08-30

Destination-currency amount = budget × exchange rate. Fee cost (home currency) = budget × fee %. Total cost including fee = budget + fee cost. Destination-currency amount after fee = destination amount × (1 − fee %).

Enter the exchange rate as destination-currency-per-home-currency — check a live rate source before a real trip, since rates move constantly and this tool doesn't fetch one automatically. Foreign transaction fees on credit/debit cards typically run 1-3% of each purchase (averaging around 1.6% across US cards as of 2026), though many travel rewards and premium cards waive this fee entirely. This tool doesn't model ATM withdrawal fees, dynamic currency conversion markups (a separate, often worse, in-person conversion trap), or day-to-day exchange-rate fluctuation during your trip.

• WalletHub — How Much Are Foreign Transaction Fees in 2026? — accessed 2026-08-30

Weekly Benefit Amount (WBA) = min((highest-quarter wages ÷ divisor) × percentage, state weekly maximum). Total potential benefit = WBA × maximum weeks payable.

Unemployment insurance is run state-by-state — the base-period definition, percentage, divisor, weekly cap, and number of payable weeks all vary by state (2025 weekly caps ranged from about $235 to over $823). Some states, like Colorado, use a different method entirely (e.g. averaging your two highest quarters). This tool is a rough estimate, not a benefits determination — eligibility, waiting weeks, and partial-benefit offsets aren't modeled. Check your state unemployment insurance agency for your actual weekly benefit amount.

• National Employment Law Project — Benefit Amounts — accessed 2026-08-31
• NJ Division of Unemployment Insurance — How we calculate benefits — accessed 2026-08-31

Commute savings = employees × commute cost/day × work weeks/year. Overhead savings = employees × (overhead/month × 12) × share avoided. Productivity value change = (employees × avg salary) × productivity % change. Total impact = commute savings + overhead savings + productivity value change.

Commute and overhead figures are mechanical estimates from your own inputs. The productivity assumption is the most uncertain part of this model — published trials (the UK's 2022 4 Day Week pilot, Microsoft Japan's 2019 trial) reported steady-to-improved output at many participating employers, but results vary significantly by role, industry, and rollout, and are not guaranteed for any given organization. This tool assumes pay is unchanged while scheduled days drop (the common '100-80-100' model) and does not model revenue effects, client-coverage gaps, or one-time transition costs.

• APA Monitor on Psychology — The rise of the 4-day workweek — accessed 2026-08-31
• Emburse — How much a 4-day work week saves on business expenses — accessed 2026-08-31

% covered = award ÷ cost of attendance × 100. Year-1 gap = cost of attendance − (award + other aid). 4-year total gap = (cost of attendance × 4) − (total award over 4 years + total other aid over 4 years), where a one-time award counts only in year 1.

Assumes cost of attendance and other aid stay flat across all 4 years — in reality tuition and fees typically rise annually and need-based aid can change with your family's circumstances, so real multi-year totals will differ from this straight-line projection. A one-time award looks identical to a renewable one in year 1; the difference only appears from year 2 onward, so confirm renewal terms (GPA minimums, credit-hour requirements, etc.) directly with the scholarship provider.

• EducationData.org — Average Cost of College — accessed 2026-08-31
• EducationData.org — College Scholarship Statistics — accessed 2026-08-31

Amount financed = price − down payment − trade-in value. Monthly payment = P × r × (1 + r)^n / ((1 + r)^n − 1), where P is the amount financed, r is the monthly rate (APR ÷ 12 ÷ 100), and n is the term in months. Total interest = (monthly payment × n) − P. Total cost = (monthly payment × n) + down payment.

Motorcycle loans typically run shorter and price higher than car loans — many lenders cap terms around 60-84 months and charge somewhat higher APRs than an equivalent car loan, since motorcycles depreciate faster and carry higher default/repossession risk. Rate and term defaults here are illustrative starting points, not a quote — your actual APR depends on your credit tier, the bike's age and mileage, and the lender.

• LendingTree — Best Motorcycle Loans — accessed 2026-08-31
• Forbes Advisor — Best Motorcycle Loans — accessed 2026-08-31

Amount financed = price − down payment − trade-in value. Monthly payment = P × r × (1 + r)^n / ((1 + r)^n − 1), where P is the amount financed, r is the monthly rate (APR ÷ 12 ÷ 100), and n is the term in months. Total interest = (monthly payment × n) − P. Total cost = (monthly payment × n) + down payment.

Unlike a car loan's typical 5-7 year term, RV and boat loans commonly stretch 10 to 20 years because loan amounts run much larger and many lenders treat these as dedicated marine/RV installment products. A longer term lowers the monthly payment but can multiply total interest paid — and RVs and boats depreciate quickly, so a 20-year loan can leave you owing far more than the vehicle is worth for much of its term. Rate and term defaults here are illustrative; get an actual quote from your lender.

• Boat Trader — Boat Loan Interest Rates in 2026 — accessed 2026-08-31
• RV Brands — 2026 RV Loan Rates & Terms — accessed 2026-08-31

Extra out-of-pocket per claim = deductible B − deductible A. Break-even years = extra per claim ÷ annual premium savings. Cumulative savings over horizon = annual premium savings × horizon years. Break-even claims over horizon = cumulative savings ÷ extra per claim. Net benefit of choosing B = cumulative savings − (expected claims × extra per claim).

This compares two deductible options for the same coverage, not whether to carry collision/comprehensive coverage at all. The break-even math assumes the premium-difference figure you enter is accurate and stays roughly constant over the horizon — insurers do reprice at renewal. Regardless of what the math says, never choose a deductible higher than you could comfortably pay in cash if a claim happened tomorrow.

• InsureCalcs — Deductible vs Premium Break-Even Calculator — accessed 2026-08-31
• Ditto — Auto Insurance Claims Statistics in 2026 — accessed 2026-08-31

Total cost = (attorney hourly rate × estimated hours) + court filing fee + mediation cost (if used).

Contested divorces cost dramatically more than uncontested ones because disputed issues mean more attorney hours, more hearings, and sometimes a trial. Actual costs vary widely by state, county, attorney experience, and how quickly both sides reach agreement.

• The Motley Fool — The Average Cost of Divorce — accessed 2026-08-31
• LegalZoom — How Much Does a Divorce Cost? The Complete Breakdown — accessed 2026-08-31

Estimated total = (bundle cost, or sum of selected document costs) × complexity multiplier.

Complexity — a blended family, out-of-state or business-owned property, or a high-net-worth estate — routinely pushes real attorney costs above a simple flat-fee package once extra drafting, tax planning, or trust funding is involved. The complexity multiplier here is illustrative, not a real quote.

• LegalZoom — How Much Does Estate Planning Cost? 2026 Guide — accessed 2026-08-31
• FindLaw — What Does an Average Estate Plan Cost? — accessed 2026-08-31

Interest = amount × annual rate × (days ÷ 365), simple interest — applied first to the pre-judgment period, then again to the post-judgment period on the resulting judgment total (principal + pre-judgment interest + costs).

Statutory judgment interest rates vary enormously by state — examples include New York at 9%/year, California at 10%/year on most money judgments, Massachusetts at 12%/year, and federal courts using the weekly 1-year Treasury rate (often under 5%). Both rate fields are fully editable — verify your own state's actual statutory rate and accrual rules before relying on this number.

• U.S. Courts — Post Judgment Interest Rate (28 U.S.C. §1961) — accessed 2026-08-31
• Steptoe — Pre- and Post-Judgment Interest Rates: Depends on the State — accessed 2026-08-31

ISA future value = balance × (1+g)^n + contribution × (((1+g)^n − 1) ÷ g), where g is the annual growth rate and n is years. The taxable-account comparison uses a reduced net growth rate g × (1 − tax rate).

This is a UK-only, GBP-only tool. The taxable-account comparison is a simplification — a flat annual tax on growth, not a precise model of dividend or capital gains tax. Unused ISA allowance does not carry forward; it resets every 6 April. Not financial or tax advice.

• gov.uk — Individual Savings Accounts (ISAs) — accessed 2026-08-31
• ii.co.uk — ISA allowance explained: limits and rules for 2026/27 — accessed 2026-08-31

Cumulative room = sum of the CRA's annual TFSA dollar limit for every year from your eligibility year through the current year. Available room now = cumulative room − lifetime contributions + prior-year withdrawals. Each projected year adds that year's new limit to room, caps your planned contribution at whatever room remains, then compounds: balance = balance × (1+g) + that year's actual contribution.

Uses the CRA's confirmed published annual limits for 2009-2026; years beyond 2026 assume the current $7,000 limit as a flat placeholder. Withdrawals restore room only starting the calendar year AFTER the withdrawal, not immediately — recontributing in the same year you withdraw, if you've already used your room, is an over-contribution subject to a 1%-per-month CRA penalty tax, which this tool doesn't model. Not financial or tax advice.

• Canada.ca (CRA) — Calculate your TFSA contribution room — accessed 2026-08-31
• Questrade — TFSA Contribution Limits 2026 — accessed 2026-08-31

Average cost per share = total cost of all lots ÷ total shares across all lots. Realized gain/loss = (shares sold × sale price) − (shares sold × average cost per share). A split of ratio r multiplies each lot's quantity by r and divides its price per share by r, leaving total cost unchanged.

This models the average cost method only, not FIFO or specific-lot identification. Canada's CRA requires average cost (adjusted cost base) for identical publicly traded securities; the U.S. IRS defaults to FIFO but permits specific-lot identification if elected. Check which method actually applies to your country, account type, and brokerage before relying on this for a tax filing. Not tax or investment advice.

• Investopedia — Average Cost Basis Method — accessed 2026-08-31
• WealthNorth — Adjusted Cost Base (ACB) in Canada — accessed 2026-08-31

Open rate = unique opens ÷ emails delivered × 100. Click-through rate (CTR) = unique clicks ÷ emails delivered × 100. Click-to-open rate (CTOR) = unique clicks ÷ unique opens × 100.

Benchmark bands are drawn from Mailchimp's published all-industry averages (open rate ~21.33%, CTR ~2.66%). Since Apple Mail Privacy Protection (2021) pre-fetches images for many subscribers, open-rate counts are inflated industry-wide — CTR and CTOR are generally considered more reliable engagement signals today.

• Mailchimp — Email Marketing Benchmarks & Industry Statistics — accessed 2026-08-31

Total engagements = likes + comments + shares. Engagement rate (by followers) = total engagements ÷ follower count × 100. Engagement rate (by reach) = total engagements ÷ reach or impressions × 100.

By-follower and by-reach engagement rate answer different questions and aren't interchangeable — by-reach is typically higher since not every follower sees every post. Platform benchmark bands are directional only: published averages vary widely by report, audience size, and content format.

• Hootsuite — Average engagement rates for 12 industries — accessed 2026-08-31
• Sprout Social — Social Media Benchmarks by Industry — accessed 2026-08-31

Cost in native token per transaction = (gas limit × gas price in gwei) ÷ 10^9. Cost in your currency = that native-token cost × the token's price.

This has no live gas-price, gas-limit, or token-price feed. Typical NFT mints range roughly 100,000-250,000 gas units versus about 21,000 for a plain transfer. Since the London upgrade (EIP-1559), a real transaction's fee is technically gas limit × (base fee + priority tip); this calculator folds both into the single 'gas price' figure you enter. Not financial advice.

• ethereum.org — Gas and fees — accessed 2026-08-31

Total portfolio value = sum of all holdings' current values. Each holding's target value = total value × (its target % ÷ sum of all target %s). Amount to buy or sell = target value − current value.

This only reallocates money already in the portfolio. It doesn't account for trading costs, bid/ask spreads, minimum lot sizes, or taxes — selling an appreciated holding in a taxable brokerage account can trigger a capital gain. Not tax or investment advice.

• Fidelity — Rebalancing your portfolio — accessed 2026-08-31

Split multiplier = new shares ÷ old shares. Post-split shares = pre-split shares × multiplier. Post-split cost basis per share = pre-split cost basis per share ÷ multiplier.

A stock split does not change the total value of your position or your total cost basis at the moment it happens. This calculator doesn't handle cash-in-lieu payments some brokers make for a fractional share a reverse split can produce. Not tax advice.

• IRS — Stocks (options, splits, traders) FAQ — accessed 2026-08-31

Monthly-equivalent cost = billed cost ÷ months in that billing cycle (1 for monthly, 3 for quarterly, 12 for annual). Total monthly spend = sum of every subscription's monthly-equivalent cost. Total annual spend = total monthly spend × 12.

This only totals what you enter — it can't discover subscriptions on your bank or card statement for you. It also doesn't judge which subscriptions are worth keeping.

• Consumer Reports — subscription creep and hidden recurring costs — accessed 2026-08-31

Drive: annual cost = ((one-way miles × 2 × workdays) ÷ mpg × gas price) + (one-way miles × 2 × workdays × per-mile wear rate) + (monthly parking × 12). Transit: annual cost = (round-trip fare × workdays) + (monthly parking × 12).

The per-mile wear-and-depreciation figure borrows the IRS standard business mileage rate (76¢/mile as of July 1, 2026) as a reasonable stand-in for maintenance, tires, and depreciation. This doesn't model rising gas prices or fares over time, tolls, or the value of your commute time itself.

• IRS — 2026 standard mileage rates (second-half increase) — accessed 2026-08-31
• IRS — Standard mileage rates — accessed 2026-08-31

Expected repair payout = probability of repair × typical repair cost. Expected value of the warranty = expected repair payout − warranty cost. Break-even probability = warranty cost ÷ typical repair cost.

A negative expected value doesn't automatically make a warranty a bad purchase — insurance and warranties are priced above the average payout because the seller needs a profit margin, and their real purpose is reducing the risk of a large, unpredictable loss.

• Consumer Reports — Extended warranties: are they worth it? — accessed 2026-08-31
• Federal Trade Commission — Auto warranties and service contracts — accessed 2026-08-31

Adjusted value = past salary × (1 + rate)^(current year − past year). Real change % = (offer ÷ adjusted value − 1) × 100.

Uses a single flat average annual inflation rate compounded across the full year span, rather than looking up actual historical year-by-year CPI-U figures. Long-run US CPI inflation has averaged roughly 2.5-3.3%/year depending on the exact period measured. This is a pre-tax, gross-salary comparison.

• USInflationCalculator.com — U.S. Inflation Rates by Year: Historical Data — accessed 2026-08-31

Replacement cost = square footage × cost per sq ft × (1 + overhead %).

Replacement cost is not market value. Market value reflects land, location, and buyer demand; replacement cost reflects only what it takes to rebuild the physical structure. This is a planning estimate — ask your insurer for a professional replacement-cost estimate before setting your policy's dwelling limit.

• The Zebra — Home Replacement Cost Calculator — accessed 2026-08-31
• ValuePenguin — Homeowners Insurance Replacement Cost Estimator — accessed 2026-08-31

Labor cost = crew size × hourly rate per mover × estimated hours. Long-distance moves multiply hours by 1.25.

This covers labor only, not a full move. It's deliberately narrower than the site's Moving Cost Calculator, which prices a full-service move with a blended crew-plus-truck rate, packing supplies, and linehaul.

• ConsumerAffairs — How Much Do Movers Cost? — accessed 2026-08-31

Cost per visit = monthly fee ÷ visits. Pay-per-visit total = visits × drop-in rate. Breakeven visits = ceiling(monthly fee ÷ drop-in rate).

This compares raw dollar cost only — it doesn't factor in contract lock-in, cancellation fees, or the convenience of not paying per session.

• GoodRx — What Is the Average Cost of a Gym Membership? — accessed 2026-08-31

Realized gain = Sale price − Adjusted basis. Boot = max(0, (Sale price − Debt paid off) − (Replacement price − New debt)). Gain recognized now = min(Boot, Realized gain). Gain deferred = Realized gain − Gain recognized now. Substituted basis = Replacement price − Gain deferred.

This is a simplified estimate, not tax or legal advice. It ignores selling/closing costs, depreciation recapture (taxed separately, up to 25%), and state-specific rules. A real 1031 exchange requires identifying replacement property within 45 days of the sale, closing within 180 days, and running the entire transaction through a qualified intermediary.

• IRS — Like-Kind Exchanges Under IRC Section 1031 — accessed 2026-08-30

Long call: P/L = max(0, Price − Strike) − Premium paid. Long put: P/L = max(0, Strike − Price) − Premium paid. Covered call: P/L = (min(Price, Strike) − Cost basis) + Premium received. Cash-secured put: P/L = Premium received − max(0, Strike − Price).

This is an expiration-only payoff model — it ignores commissions, assignment fees, time value remaining before expiration, taxes, and dividends. A long call's max profit is unlimited since the underlying has no price ceiling.

• Investopedia — Covered Call: How It Works and Examples — accessed 2026-08-30

Loop factor = Rate(A→B) × Rate(B→C) × Rate(C→A). Deviation from parity = (Loop factor − 1) × 100%.

This is an educational illustration, not a real trading tool. It ignores bid/ask spread, fees, and slippage. Real-world triangular arbitrage opportunities in major currencies are extremely rare and closed within milliseconds by high-frequency trading firms.

• Investopedia — Triangular Arbitrage Definition — accessed 2026-08-30

Income as % of FPL = household income ÷ Federal Poverty Line for your household size × 100. Expected annual contribution = income × applicable percentage (a flat 2.10% below 133% FPL, ramping up to 9.96% at 300%-400% FPL). Monthly premium tax credit = benchmark premium − (expected annual contribution ÷ 12), floored at $0.

Uses the 2026 IRS applicable-percentage table (Rev. Proc. 2025-25) and the 2025-published HHS federal poverty guidelines — the guidelines that actually govern 2026 coverage-year eligibility. Above 400% FPL there's currently no subsidy at all — the enhanced subsidies from 2021-2025 expired at the end of 2025 and were not extended. This is a rough planning estimate, not an eligibility determination.

• IRS — Rev. Proc. 2025-25 (2026 applicable percentage table) — accessed 2026-08-31
• HealthCare.gov — how premium tax credits work — accessed 2026-08-31

Break-even (months) = closing costs ÷ monthly payment savings. Total net savings over your plan = (monthly savings × months in your plan) − closing costs.

This is the simplest, most commonly cited refinance break-even method. It doesn't discount future savings to present value, account for a change in loan term length, or model taxes.

• Chase — Calculating the break-even point when refinancing — accessed 2026-08-31

Your income tier is determined by comparing your MAGI from two years prior against six CMS-published brackets. Each bracket sets a fixed total Part B premium and, optionally, a fixed Part D surcharge. The IRMAA surcharge shown is your tier's total Part B premium minus the standard $202.90 premium.

IRMAA is assessed on your MAGI from two years earlier — 2026 premiums use your 2024 tax return. If your income has since dropped due to a qualifying life event, you can request a redetermination using SSA Form SSA-44. Married filing separately uses a much lower, different income threshold not modeled here.

• CMS — 2026 Medicare Parts B Premiums and Deductibles (fact sheet) — accessed 2026-08-31

Cost per guest = total event budget ÷ guest count. Per-category cost per guest = that category's budget ÷ guest count.

Unlike a fixed percentage split, each category here is a direct dollar entry — the right mix between venue, catering, and entertainment varies enormously by event type, so there's no single allocation heuristic that fits a corporate event, a gala, and a birthday party equally well.

• Wikipedia — Event management — accessed 2026-08-31

Monthly cost = (adults × per-adult monthly cost + children × per-child monthly cost) × household-size adjustment factor. Adjustment: 1-person +20%, 2-person +10%, 3-person +5%, 4-person no adjustment, 5-6 person −5%, 7+ person −10%.

USDA republishes these Food Plan costs monthly using CPI-U data, so current-month figures will drift slightly. Thrifty Plan figures are U.S. Average, January 2025 data; Low-Cost/Moderate/Liberal figures are U.S. Average, December 2025 data.

• USDA Food and Nutrition Service — Official USDA Food Plans: Cost of Food at Home at Three Levels — accessed 2026-08-31
• USDA FNS — USDA Food Plans: Monthly Cost of Food Reports — accessed 2026-08-31

Ongoing annual cost = food + routine vet care + grooming + supplies & misc. + pet insurance (if selected). First-year total = ongoing annual cost + one-time setup cost. Lifetime cost = one-time setup cost + (ongoing annual cost × expected lifespan in years).

These are illustrative national-average estimates synthesized from several industry cost-of-ownership sources, not a single official dataset. Unexpected costs (an emergency surgery, a chronic condition) aren't included in 'routine vet care' — that's the gap pet insurance or a dedicated emergency fund is meant to cover.

• ASPCA — Cutting Pet Care Costs — accessed 2026-08-31
• Pawlicy Advisor — How Much Pet Insurance Costs in 2026 — accessed 2026-08-31

Value after year 1 = purchase price × (1 − year-1 rate). Value after each subsequent year = prior year's value × (1 − later-year rate).

Depreciation is modeled as two flat rates — a widely-cited simplification, not a per-model curve. Real depreciation varies enormously by make, model, mileage, condition, and market demand.

• LendingTree — Car Depreciation: How Much Is My Car Worth? — accessed 2026-08-30

Expected mileage for age = age × 12,000. Mileage adjustment % = −(actual − expected) ÷ 1,000 × 0.5%, clamped between −30% and +15%. Adjusted value = baseline × (1 + mileage adjustment%) × condition multiplier. Trade-in estimate = adjusted value × (1 − dealer discount %).

This is a rough estimate, not an appraisal. Dealers typically offer meaningfully less than private-party value — commonly cited at roughly 10-20% below.

• Speck Buick GMC — KBB Trade-In Value vs Private Party Value — accessed 2026-08-30

Monthly cost (daily mode) = daily rate × days per week × (52 ÷ 12). Monthly cost (permit mode) = the flat monthly rate entered directly. Annual cost = monthly cost × 12.

A simple cost comparison only — it doesn't account for driving costs (fuel, wear, tolls) or time/convenience differences between driving and transit.

• American Public Transportation Association — Public transit statistics — accessed 2026-08-30

Base monthly rate (at $500,000 coverage, 20-year term) is looked up by age and sex, interpolated between the nearest sourced ages. That base rate is scaled to your coverage amount, then multiplied by a term-length factor (10yr ≈0.71x, 20yr =1.0x, 30yr ≈1.75x) and, if applicable, a smoker multiplier (≈3.3x).

This is an illustrative, directional estimate — not a real quote. Real premiums come from full underwriting: a medical exam, family health history, occupation/hobby risk factors, and the insurer's own rate class. Get quotes from at least 2-3 real insurers.

• MoneyGeek — Term Life Insurance Rates by Age Chart (2026) — accessed 2026-08-30

Annual premium = national-average base premium × (your coverage ÷ base coverage) × state-cost-tier multiplier × (homeowners only) claims-history multiplier.

This is an illustrative, directional estimate — not a real quote. Real premiums come from an insurer's underwriting of construction type/age/roof condition, exact location risk zones, credit-based insurance score, deductible, and bundling discounts.

• NerdWallet — How Much Is Homeowners Insurance? Average 2026 Rates — accessed 2026-08-30
• Insurance.com — How much is renters insurance in 2026? — accessed 2026-08-30

Monthly benefit = gross annual income × replacement ratio ÷ 12. Annual premium = gross annual income × premium rate (1-3%, by tier). Monthly income gap = gross annual income × (1 − replacement ratio) ÷ 12.

This is an illustrative, directional estimate — not a real quote. Insurers deliberately cap LTD benefits below 100% of income (typically 60-70%) so returning to work stays financially preferable to remaining on claim.

• Guardian Life — How Much Disability Insurance Do I Need? — accessed 2026-08-30

Gross rental yield = (monthly rent × 12) ÷ property value × 100. Net rental yield = ((monthly rent × 12) − annual operating costs) ÷ property value × 100.

Gross yield is what most listing sites quote — simple but ignores every ongoing cost. Net yield subtracts operating costs and is always the lower, more realistic figure. Neither includes mortgage payments or purchase/closing costs.

• Investopedia — Rental Property ROI and Yield Explained — accessed 2026-08-30

NOI = annual rental income − annual operating expenses (excluding debt service and capex). Cap rate = NOI ÷ current property value × 100.

Cap rate is calculated before financing — NOI excludes mortgage principal/interest and capex by standard convention. This makes it ideal for comparing properties, but it's NOT your actual cash return if you have a mortgage — see Landlord ROI for that.

• BiggerPockets — Cap Rate: What It Is and How to Calculate It — accessed 2026-08-30

Total cash invested = down payment + closing costs + initial repairs. Monthly cash flow = rent − operating expenses − mortgage payment. Cash-on-cash return = (monthly cash flow × 12) ÷ total cash invested × 100.

Cash-on-cash return divides by your actual cash invested, not the full purchase price, since the rest is financed — distinguishing it from cap rate. A commonly cited target is roughly 8-12%. This is a pre-tax estimate that doesn't account for appreciation or principal paydown.

• Investopedia — Cash-on-Cash Return Definition and Formula — accessed 2026-08-30
• Rabbu — What Is a Good Cash-on-Cash Return? — accessed 2026-09-01

Accrual per paycheck = annual allowance ÷ pay periods per year. Accrued to date = accrual per paycheck × pay periods elapsed, capped at the accrual cap if set. Hours available = accrued to date − hours used.

This models a simple linear accrual, the most common US structure. It doesn't model front-loaded PTO, tenure-based accrual-rate increases, or year-end forfeiture.

• U.S. Department of Labor — Vacation Leave — accessed 2026-08-30

Tenure-based weeks = years of service × weeks per year. Total weeks = max(tenure-based weeks, guaranteed minimum weeks). Severance pay = total weeks × weekly pay.

In most of the US, there's no general legal requirement for severance — it's typically discretionary. '1-2 weeks per year of service' is a commonly cited industry convention, not a legal formula. The federal WARN Act requires 60 days' notice before a qualifying mass layoff (100+ employee employers), separate from severance itself.

• U.S. Department of Labor — WARN Act — accessed 2026-08-30

New salary = current salary + raise amount. Nominal raise % = raise amount ÷ current salary × 100. Real change % = (1 + nominal % ÷ 100) ÷ (1 + inflation % ÷ 100) − 1, × 100.

This is a pre-tax, gross-salary comparison. The inflation rate is an assumption you control, not a guaranteed future figure.

• Bureau of Labor Statistics — Consumer Price Index (CPI) overview — accessed 2026-08-30

Customer churn rate = customers lost ÷ customers at start × 100. Revenue churn rate = MRR lost ÷ MRR at start × 100. Implied average customer lifespan (months) = 100 ÷ monthly customer churn rate.

Customer churn and revenue churn commonly diverge, since lost accounts aren't all the same size. The implied lifespan assumes a constant churn rate every month. Revenue churn here measures MRR actually lost only, not net movement including expansion.

• ChartMogul — Churn Rate: How to Calculate and Reduce Customer Churn — accessed 2026-08-30

Flat: commission = sale amount × rate %. Tiered: commission = min(sale, quota) × base rate % + max(0, sale − quota) × accelerator rate %.

Real sales compensation plans vary widely — some apply accelerators retroactively to the whole sale, others cap total commission or claw it back on a cancelled deal. Check your actual comp plan.

• Investopedia — How Does a Company Determine Sales Commission Structure? — accessed 2026-08-30

Monthly payment = P × r × (1+r)^n ÷ [(1+r)^n − 1]. Annual debt service = monthly payment × 12. DSCR = annual NOI ÷ annual debt service.

1.25x is a commonly cited minimum DSCR, though the real requirement varies by lender and loan type. This calculator covers only this one loan's debt service, not a business's total debt obligations.

• U.S. Small Business Administration — SBA 7(a) loan program requirements — accessed 2026-08-30
• Re-Leased — Debt Service Coverage Ratio (DSCR) Explained — accessed 2026-09-01

Add mode: tax amount = price × (rate ÷ 100); total = price + tax amount. Extract mode: pre-tax price = total ÷ (1 + rate ÷ 100); tax amount = total − pre-tax price.

State rates shown are averages (Tax Foundation, as of July 1, 2026), not exact ZIP-code figures — county, city, and special-district taxes stack on top, and many states exempt or partially tax categories like groceries or clothing. Confirm your local rate before relying on this for a real transaction.

• Tax Foundation — State and Local Sales Tax Rates — accessed 2026-08-30

PIA (2026 bend points): 90% of AIME up to $1,286, plus 32% of AIME between $1,286 and $7,749, plus 15% above $7,749 — rounded down to the nearest $0.10. Monthly benefit = PIA × a claiming-age factor (0.70 at 62, rising to 1.0 at Full Retirement Age 67, up to 1.24 at 70).

This is a simplified educational illustration built on the real SSA benefit-formula structure — not a personalized prediction. It assumes a flat AIME you type in, assumes FRA = 67 (true only for people born 1960 or later), and doesn't account for spousal/survivor benefits, WEP, COLA, or taxation of benefits. For your real number, use your ssa.gov 'my Social Security' account.

• Social Security Administration — Benefit Formula Bend Points — accessed 2026-08-30
• Social Security Administration — Full Retirement Age chart — accessed 2026-08-30

Add VAT: VAT amount = net price × (rate ÷ 100); gross price = net price + VAT amount. Extract VAT: net price = gross price ÷ (1 + rate ÷ 100); VAT amount = gross price − net price.

Rates shown are standard national rates from a mid-2026 survey, illustrative not exhaustive. Most countries also apply reduced or 0% rates to specific categories. VAT-registered retail prices outside the US are normally already VAT-inclusive, unlike US sales tax. Confirm the current rate before relying on this for a real transaction.

• European Commission — VAT rates applied in the Member States of the EU — accessed 2026-08-30
• GOV.UK — VAT rates — accessed 2026-08-30

ROAS = revenue ÷ ad spend. Gross profit = revenue × gross margin %. Break-even ROAS = 1 ÷ gross margin % — the minimum ROAS at which ad spend is fully offset by gross profit. Net profit after ads = gross profit − ad spend.

ROAS by itself doesn't account for the cost of goods sold — a 4x ROAS looks strong, but at a 20% gross margin the true break-even ROAS is 5x. 'Good' ROAS benchmarks vary enormously by industry, platform, and business model.

• WordStream — What Is ROAS & How Do I Calculate It? — accessed 2026-08-30

CPM = (ad spend ÷ impressions) × 1,000. Impressions = (budget ÷ target CPM) × 1,000. Budget = (target CPM × impressions) ÷ 1,000.

CPM (cost per mille) is the standard way display, video, and social advertising is priced. CPM benchmarks vary enormously by platform, targeting, format, industry, and season — there is no single universal 'good' CPM figure.

• Google Ads Help — About CPM bidding — accessed 2026-08-30

CTR = (clicks ÷ impressions) × 100. CPC = ad spend ÷ clicks. CPM = (ad spend ÷ impressions) × 1,000.

'Good' CTR varies enormously by platform, ad format, industry, and placement — search ads typically see far higher CTR than display or social ads shown to a passive audience.

• HubSpot — What Is Click-Through Rate (CTR) & How to Calculate It — accessed 2026-08-30

Subtotal = sum of all 7 category totals. Buffer amount = subtotal × buffer %. Total budget = subtotal + buffer amount. Per traveler = total ÷ travelers. Per day = total ÷ trip length.

Enter each category as a trip-wide total already covering every traveler. A 10-15% contingency buffer is a common planning practice. Actual costs vary enormously by destination, season, and travel style.

• NerdWallet — How to Budget for a Vacation — accessed 2026-08-30

Value redeemed = cash price − cash fees. Value per point (cents) = (value redeemed ÷ points used) × 100.

'Good value' benchmarks vary meaningfully by loyalty program — a hotel program valued at 0.5 cents/point has a very different bar than one valued at 2 cents/point. This tool uses a general cross-program benchmark, not a program-specific one.

• The Points Guy — How TPG calculates points and miles valuations — accessed 2026-08-30

Nisab value = Nisab weight × current price per gram. Gross assets = cash + gold/silver value + investments + business inventory. Net Zakatable wealth = gross assets − short-term debts. If net wealth ≥ Nisab value: Zakat due = net wealth × 2.5%.

Zakat is due once net Zakatable wealth has remained at or above the Nisab threshold for one full lunar (Hijri) year, not the Gregorian calendar year. Specific fiqh rulings can vary by school of thought and individual scholarly opinion — consult a knowledgeable local imam or Islamic scholar for anything consequential.

• Islamic Relief USA — Zakat Calculator methodology — accessed 2026-08-30
• Zakat Foundation of America — How to calculate Zakat — accessed 2026-08-30

Rule of 72 estimate (years) = 72 ÷ annual rate. Actual precise doubling time (years) = ln(2) ÷ ln(1 + rate).

The Rule of 72 is most accurate in the commonly cited 6-10% range. It gets noticeably less precise at very low rates (under ~2%) or very high rates (above ~20%). 69.3 is actually the more mathematically exact numerator for continuous compounding; 72 is preferred because it divides evenly by more small whole numbers.

• Investopedia — Rule of 72 Definition, Formula, and Example — accessed 2026-08-30