Can I use negative numbers?

Yes — enter a negative numerator or denominator and the sign carries through the calculation correctly.

What happens if I divide by a fraction with a zero numerator?

That's undefined, and the tool shows the result as undefined rather than a number.

Can I enter improper fractions, like 7/3?

Yes — any numerator and denominator combination works, whether the fraction is proper, improper, or negative.

How does the chart change based on my result?

A result between 0 and 1 shows a filled donut chart; a result outside that range switches to a comparison-bar view, since a donut doesn't represent values over 100% intuitively.

How is a fraction actually simplified to lowest terms?

By dividing both the numerator and denominator by their greatest common divisor (GCD) — for example, 8/12's GCD is 4, giving 2/3.

Can I add a whole number to a fraction, like 2 + 1/3?

Enter the whole number as a fraction over 1 (2/1) in the first field, then add 1/3 — the result correctly comes out as 7/3.

Why is my decimal equivalent a repeating number, like 0.333...?

Some fractions, like 1/3, don't terminate in decimal form — the tool rounds the displayed decimal for readability, but the exact value is the simplified fraction shown alongside it.

Does denominator order matter when dividing fractions?

Yes — dividing by a fraction means multiplying by its reciprocal (flipping numerator and denominator), so (a/b) ÷ (c/d) is not the same as (c/d) ÷ (a/b) unless both fractions are equal.

Fraction Calculator

About the Fraction Calculator

Adds, subtracts, multiplies, or divides two fractions and simplifies the result to lowest terms, also showing the decimal equivalent.

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

How to use it

Enter the first fraction's numerator and denominator.
Choose an operator (+, −, ×, ÷).
Enter the second fraction's numerator and denominator.
Read the simplified result and decimal equivalent in the readout.

Formula

Addition/subtraction: a/b ± c/d = (ad ± bc)/bd
Multiplication: (a/b)×(c/d) = ac/bd
Division: (a/b)÷(c/d) = ad/bc
Simplify by dividing both parts by their greatest common divisor.

Worked example

1/2 + 1/3 = (1×3 + 1×2)/(2×3) = 5/6.

Recommendations

• Enter whole numbers as a fraction over 1, like 5/1, if you need to mix whole numbers with fractions.
• The result simplifies automatically — no need to reduce by hand first.
• For a fraction of a specific number rather than fraction arithmetic, use the Percentage Calculator instead.

Frequently asked questions

You can enter any fraction, even an unreduced one — the calculator always simplifies the final result automatically.

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