∞ GCD & LCM
Greatest common divisor and least common multiple
About this calculator
The greatest common divisor (GCD) is the largest number that divides two numbers evenly; the least common multiple (LCM) is the smallest number both divide into. Enter two or more integers and the calculator finds both, using the Euclidean algorithm — the fast, classic method of repeated division. Useful for simplifying fractions, scheduling repeating events, or splitting quantities evenly between groups.
Tip: the two are linked — GCD × LCM always equals the product of the two numbers, a handy way to double-check your answer.