Fraction Calculator

When this tool is useful

Use the fraction calculator to add, subtract, multiply or divide rational values while keeping the reduced numerator and denominator visible.

How to use it

1. Enter two numerators and denominators using non-zero denominators.
2. Choose an operation and run the calculation.
3. Check the reduced result and convert it to a decimal only when that form is useful for your next step.

Checks before you rely on the result

• The sign is normalised and the result is reduced by the greatest common divisor.
• A zero denominator is invalid rather than treated as infinity.
• Very large values may exceed safe integer precision; the tool refuses unsafe input.

This page is maintained with the tool implementation and its deterministic tests. If the result looks wrong, report the issue with a non-sensitive example.