What if my target percentages don't add up to 100%?

The calculator normalizes them proportionally so the buy and sell amounts still net to zero.

Why does rebalancing mean selling my best performers?

Because they grew fastest, they now make up a larger share of your portfolio than intended — selling some back to target locks in gains and keeps your risk level from drifting higher than planned.

How often should I rebalance?

There's no universal answer — common approaches are a fixed schedule (e.g. annually) or a threshold trigger (e.g. whenever a holding drifts more than 5 percentage points from target).

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Finance

Portfolio Rebalancing Calculator

Exactly how much to buy or sell of each holding to return a drifted portfolio to target.

🔒 Runs entirely in your browser — nothing here is ever uploaded

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Last reviewed 2026-08-31

About the Portfolio Rebalancing Calculator

Calculates exactly how much of each holding to buy or sell to bring a portfolio that's drifted from its target allocation back in line, from each holding's current dollar value and its target percentage of the whole.

100% Free Runs in Your Browser No Sign-Up Required

How to use it

List each holding with its current dollar value.
Enter each holding's target allocation as a percentage of the whole portfolio.
Add or remove holdings as needed.
Read each holding's buy or sell amount needed to reach its target.

Formula

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.

Worked example

A $10,000 portfolio: $7,000 in US stocks (60% target), $2,000 in bonds (30% target), $1,000 in international (10% target): sell $1,000 of US stocks, buy $1,000 of bonds, hold international unchanged.

Interpreting your result

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.

Recommendations

• A common rule of thumb is to rebalance when a holding drifts more than about 5 percentage points from its target, or on a fixed schedule.
• If your target percentages don't add up to exactly 100%, this tool normalizes them proportionally.
• Consider directing new contributions toward whatever's currently underweight instead of selling appreciated holdings.

Frequently asked questions

No — it only calculates the dollar amounts needed to reach your target allocation.