Least Common Multiple Calculator

What Is the Least Common Multiple?

The least common multiple (LCM) of a set of numbers is the smallest positive number that all of them divide into evenly. It's commonly used to find a common denominator when adding or subtracting fractions, and to work out when repeating events line up (e.g. two events that repeat every 4 and 6 days both fall on the same day every 12 days).

How It's Calculated

This calculator finds the LCM pairwise using the relationship LCM(a,b) = (a × b) ÷ GCD(a,b), then combines each additional number into the running result the same way, so it works for any list of two or more whole numbers.