Find the greatest common divisor (GCD, also called the highest common factor) and the least common multiple (LCM) of a set of whole numbers. Enter two or more integers separated by commas or spaces and the calculator returns both values. The GCD is the largest number that divides all of them evenly, which is exactly what you need to reduce fractions or split things into equal groups. The LCM is the smallest number they all divide into, useful for adding fractions or finding when repeating cycles line up. The calculation uses the fast Euclidean algorithm and extends cleanly to any number of inputs. Enter your integers and both results appear instantly, computed locally in your browser.