LCM Calculator — Least Common Multiple Finder

Reviewed August 7, 2026

ResultUpdates as you type

Least Common Multiple (LCM)60

Greatest Common Factor (GCF)1

Count3

Find the Least Common Multiple (LCM) of two or more numbers using prime factorization and the GCF formula method.

Calculate the Least Common Multiple (LCM) of two or more numbers along with their Greatest Common Factor (GCF).

Understanding Least Common Multiple (LCM)

The Least Common Multiple (LCM) of a set of integers is the smallest positive integer that is a multiple of all numbers in the set.

Using GCF: For two numbers a and b, LCM(a,b) = (a × b) / GCF(a,b).
Prime Factorization: Factorize each number into prime factors and take the maximum power of every prime factor present across the numbers.

LCM Formula via GCFLCM(a, b) = (|a × b|) / GCF(a, b)Calculate LCM by dividing product by GCF.

Prime Factorization MethodLCM = product of highest powers of all prime factorsMultiply each prime factor raised to its maximum exponent.

Multiples of 12: 12, 24, 36, 48, 60. Multiples of 15: 15, 30, 45, 60. Multiples of 20: 20, 40, 60. LCM = 60.

What is LCM?

The LCM (Least Common Multiple) is the smallest positive integer that is divisible by each of the given numbers without a remainder.

Why is LCM useful?

LCM is essential for finding common denominators when adding or subtracting fractions with different denominators.