Math
Add, subtract, multiply, or divide two fractions and reduce the result to its simplest form.
Results update as you type. No calculate button. All calculations run locally in your browser.
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Enter two fractions above.
| Step | Value |
|---|---|
| Before simplifying | — |
| Greatest common divisor | — |
| Simplified result | — |
| Decimal value | — |
| Mixed number | — |
A mixed number is shown only when the result is improper (|numerator| > denominator). A whole-number result is shown as, for example, 2.
Add: a/b + c/d = (ad + bc) / bd. Subtract: a/b − c/d = (ad − bc) / bd. Multiply: a/b × c/d = ac / bd. Divide: a/b ÷ c/d = ad / bc. In every case, divide the resulting numerator and denominator by their greatest common divisor (GCD) to simplify, keeping any minus sign in the numerator.
1/2 + 1/3 = (1×3 + 1×2) / (2×3) = 5/6. The GCD of 5 and 6 is 1, so 5/6 is already simplest, and its decimal value is 0.833333… (shown as 0.8333). Use Reset example above to reproduce this result, then replace the values with your own.
Inputs may be whole numbers, negatives, or decimals; a decimal input is first converted to an exact fraction only when it has a short decimal expansion, otherwise the calculation uses the decimal value directly and the fraction shown is the result of the arithmetic rounded for display. Denominators must not be zero, and division also requires a nonzero second numerator. Results are rounded to 4 decimal places for display only; the underlying fraction is exact for integer inputs.
The result is not shown. A fraction with a zero denominator is undefined, so the page asks for a nonzero denominator instead of inventing a number.
By the greatest common divisor: for example 4/6 divides by GCD 2 to give 2/3. The sign is kept in the numerator, so −1/2 and 1/−2 both display as −1/2.
Fractions such as 1/3 have no exact finite decimal. The decimal shown is rounded to 4 places (0.3333); the fraction itself, 1/3, is the exact answer.
Yes. Enter a negative numerator (or denominator); the result is normalised so the denominator stays positive.
A whole part plus a fraction, for example 7/3 = 2 1/3. It is shown for improper results; proper fractions and whole numbers are shown as they are.
Results are estimates only and do not constitute professional advice.