About the LCM calculator
This free LCM calculator finds the Least Common Multiple (LCM) of two or more positive integers. The LCM is the smallest positive integer that is a multiple of each of the given numbers. You enter the numbers separated by commas or spaces (e.g. 4, 6, 8), click Get result, and the tool shows LCM(numbers) = result. The calculator uses the formula LCM(a, b) = |a × b| / GCF(a, b) and extends it to more than two numbers by taking LCM in pairs. No sign-up is required; it is mobile-friendly and runs in your browser.
The LCM is used to add or subtract fractions with different denominators (find a common denominator), to solve problems about repeating events (e.g. when two bells ring together again), and in number theory. For example, LCM(4, 6) = 12, so 1/4 + 1/6 = 3/12 + 2/12 = 5/12. For more than two numbers, the LCM is computed by repeatedly taking the LCM of pairs: LCM(a, b, c) = LCM(LCM(a, b), c). This calculator handles any number of integers and displays the result clearly.
Use this LCM calculator for homework, fractions, or any time you need the least common multiple of two or more numbers. Enter at least two positive whole numbers; non-integers and negative values are ignored. For the greatest common factor (GCF) of the same numbers, use the GCF calculator. The LCM calculator is free, responsive on phones and tablets, and requires no account.
The relationship GCF(a, b) × LCM(a, b) = |a × b| holds for two numbers, so you can get one from the other. This LCM calculator computes the LCM directly and works for any number of integers. Pair it with the GCF calculator when you need both for simplifying fractions or solving problems.