Enter values and select Calculate.
Calculated result
Formula and worked example
Find gcd(|numerator|, |denominator|), divide both components by that value, and move any negative sign to the numerator.
8/12 reduces to 2/3. The input 10/−15 normalizes to −2/3, while −10/−15 becomes 2/3.
Integer and sign policy
Numerator and denominator must be complete integers; malformed decimals are rejected.
The reduced denominator is always positive.
A zero numerator is displayed as 0 with the canonical reduced form 0/1.
Large integers and mixed numbers
Components may contain up to 200 digits and are simplified with integer-safe BigInt arithmetic.
An improper result also receives a mixed-number representation when it has a nonzero remainder.
This page reduces one fraction; it does not perform mixed-number arithmetic.
Conversion boundaries
Decimal to Fraction owns conversion from decimal notation.
Fraction to Decimal owns decimal expansion and repeating-cycle detection.
GCF Calculator owns general greatest-common-factor work, although the same mathematical operation supports fraction reduction.
Methodology and limits
This deterministic browser-local tool uses strict complete-value parsing and the displayed mathematical definition. It does not evaluate expressions, execute entered text, call a remote service, or silently cross its documented real-number or integer domain.