GCD and LCM
Enter two or more whole numbers. Results update live.
Enter at least two whole numbers.
Find the greatest common divisor and least common multiple of any set of numbers, with the working shown.
Enter two or more whole numbers. Results update live.
Pairs are folded left to right with Euclid's algorithm for the GCD, and each LCM comes from the identity lcm(a,b) = |a*b| / gcd(a,b). The step-by-step panel shows every pairwise reduction, so you can follow the exact working.
The GCD simplifies fractions and finds common factors; the LCM finds common multiples for scheduling cycles, gear ratios and repeating events. Both accept any count of whole numbers, including negatives and zero.