Fraction Calculator

Calculate fractions with steps

Add, subtract, multiply or divide two fractions. See the simplified result first, followed by the calculation steps.

First fraction
Second fraction

Enter integers only, without separators. For negative two and one-third, enter −2 as the whole-number part, 1 as the numerator and 3 as the denominator. The negative sign applies to the entire mixed number.

How to use the fraction calculator

Enter the numerator and denominator for each fraction, choose an operation and select Calculate fractions. Leave the optional whole-number fields blank for ordinary fractions. Each field accepts an integer of up to 18 digits, with an optional minus sign and no decimal point or thousands separators.

The simplified fraction is the exact answer. The calculator also shows a mixed-number form when there is a nonzero whole-number part and a remainder, plus a decimal representation. Use Copy result and steps to copy the explanation, or Use example to try 2/5 + 1/3 = 11/15.

Add or subtract fractions

Use a common denominator before combining the numerators. For 2/5 + 1/3, a common denominator is 15. Rewrite the fractions as 6/15 and 5/15, then add the numerators to obtain 11/15. Subtraction follows the same process with subtraction in the numerator.

Multiply or divide fractions

To multiply, multiply the numerators and multiply the denominators, then simplify. For example, 4/10 × 5/7 = 20/70 = 2/7.

To divide, multiply the first fraction by the reciprocal of the second. For example, 1/2 ÷ 3/4 = 1/2 × 4/3 = 2/3. The second fraction must have a nonzero value, because division by zero is undefined. See OpenStax’s explanation of fraction multiplication and division.

Mixed numbers and negative signs

A mixed number combines a whole number and a fraction. Enter 2, 1 and 3 in the first fraction’s fields to represent 2 + 1/3. To represent its negative, enter −2, 1 and 3. The calculator interprets that as −(2 + 1/3) = −7/3, rather than −2 + 1/3.

When the whole-number part is nonzero, put the sign there and enter a nonnegative numerator and positive denominator. For a negative proper fraction such as −1/3, leave the whole-number field blank and put the minus sign on the numerator. An ordinary negative denominator is normalized to a positive denominator.

Simplification, equivalence and decimals

The calculator divides the result’s numerator and denominator by their greatest common divisor (GCD, also called greatest common factor). The equivalence check compares the two original entered values; it is separate from the answer to the selected operation.

Terminating decimals are labeled exact. Repeating or longer decimals are truncated after 12 decimal places and labeled as approximations with an ellipsis. For example, 1/3 is displayed as 0.333333333333…; the exact result remains 1/3. This decimal is truncated, not rounded.

Privacy and language

Calculations run in your browser with integer arithmetic. The temporary history keeps up to eight calculations in memory for this page and disappears when you reload. The calculator does not submit the entered fractions to our server or save the history in browser storage.

The Portuguese fraction calculator uses the same arithmetic code. English uses a decimal point; Portuguese uses a decimal comma. Switching language opens the equivalent page without transferring your entries.

Frequently asked questions

How do I add fractions with different denominators?

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Rewrite the fractions with a common denominator, add the numerators and simplify. For example, 2/5 + 1/3 = 6/15 + 5/15 = 11/15.