LCM and GCD calculator

GCD (greatest common divisor)6

LCM (least common multiple)72

The GCD is the largest number that divides all of them; the LCM is the smallest number that is a multiple of all of them. Enter two or more positive integers.

This LCM and GCD calculator works out the least common multiple (LCM) and the greatest common divisor (GCD) of two or more numbers at once.

Divisors and multiples, instantly

The GCD and the LCM show up constantly when working with fractions and maths problems. This calculator finds them for as many numbers as you need, entirely in your browser.

FAQ

What are the LCM and the GCD?

The GCD (greatest common divisor) is the largest number that divides all of them exactly; the LCM (least common multiple) is the smallest number that is a multiple of all of them.

What are they used for?

The GCD is used to simplify fractions; the LCM to add fractions with different denominators and in problems involving repeating cycles.

How many numbers can I enter?

Two or more positive integers, separated by commas or spaces. The result updates as you type.