Math tool
GCD & LCM Calculator
Enter two or more numbers, separated by commas, to find their GCD and LCM.
—GCD
—LCM
What GCD and LCM are for
GCD (greatest common divisor) is the largest number that divides all inputs evenly — useful for simplifying fractions. LCM (least common multiple) is the smallest number that all inputs divide into evenly — useful for finding a common denominator or a shared repeating cycle.