Simplify a fraction by dividing the numerator and denominator by their greatest common divisor.
Last updated: June 2026 | By Patchworkr Team
A fraction is in lowest terms when the numerator and denominator share no common factor other than 1. The fraction is simplified by dividing both parts by their greatest common divisor.
12/18 simplifies to 2/3 because the GCD is 6.
Can the fraction be improper?
Yes. Improper fractions are valid and can still be reduced to lowest terms.
What if the denominator is negative?
The calculator normalizes the sign so the denominator is positive in the final result.
Does the tool accept decimals?
No. This calculator is for integer fractions only, because lowest terms are defined by whole-number divisors.
Why reject zero denominator?
Division by zero is undefined, so a zero denominator is treated as invalid input.
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