LCM Calculator
Find the Least Common Multiple (LCM) that is a multiple of two numbers.
What is Least Common Multiple (LCM)?
The Least Common Multiple (LCM) is the smallest positive integer that is divisible by all numbers in a given set. For example, the multiples of 4 are 4, 8, 12, 16, 20, 24, and the multiples of 6 are 6, 12, 18, 24. The common multiples are 12, 24, 36... so LCM(4, 6) = 12.
Finding the LCM is important for adding or subtracting fractions with unlike denominators, converting measurements, and aligning recurring schedules.
Visualizing LCM on a Number Line
Common multiples are places where both timelines align. The first alignment is the LCM.
Multiples of 4
4812162024
Multiples of 6
6121824
LCM (4,6) = 12
Examples of Least Common Multiple
Check how LCM is computed for popular number pairs.
LCM(4, 6)12
Multiples of 4: 4, 8, 12... Multiples of 6: 6, 12... The first common multiple is 12.
LCM(12, 18)36
LCM(15, 20)60
Frequently Asked Questions
They are related by: LCM(a, b) × GCF(a, b) = a × b. Thus, LCM = (a × b) / GCF.