Does this handle more than 2 numbers?

Yes — it reduces the GCD pairwise across the entire list, so any number of inputs works, not just two.

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Math & Everyday

GCF Calculator

Greatest common factor of two or more numbers, via the Euclidean algorithm.

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About the GCF Calculator

Finds the greatest common factor of two or more numbers, using the Euclidean algorithm.

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How to use it

Enter two or more positive whole numbers, separated by commas or spaces.
Read the greatest common factor of the full list.

Formula

Euclidean algorithm: gcd(a,b) = gcd(b, a mod b), repeated until the remainder is 0; applied pairwise across the full list.

Worked example

The GCF of 48, 60, and 18 is 6.

Interpreting your result

This is the same method used internally by the Ratio Calculator and Fraction Calculator to simplify results.

Frequently asked questions

GCF (greatest common factor) is the largest number that divides all inputs evenly; LCM (least common multiple) is the smallest number all inputs divide into evenly — a different, related calculation.