Enter two or more whole numbers to find their least common multiple.

The least common multiple

The least common multiple of a set of whole numbers is the smallest number that each of them divides into evenly. For four, six, and eight it is twenty four. The most familiar use is finding a common denominator so that fractions with different bottoms can be added or compared.

It also appears in scheduling problems, such as working out when two repeating events line up again. The calculator builds the result step by step using the relationship between the least common multiple and the greatest common factor.

The formula

lcm(a, b) = a x b / gcd(a, b), applied across all numbers

Worked example

The least common multiple of 4, 6, and 8 is 24.

How to read your result

The least common multiple is the smallest number all your inputs divide into evenly. It is the key to adding fractions with different denominators.

Frequently asked questions

What is the LCM used for?
Most commonly to find a common denominator when adding or comparing fractions.
Does order matter?
No, the result is the same regardless of input order.
Can I enter more than two numbers?
Yes, the calculator handles any list of whole numbers.

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