Can I enter more than 2 numbers?

Yes — enter any number of positive integers (2 or more), separated by commas; the LCM is reduced pairwise across the whole list.

Why do I need the LCM when adding fractions?

The LCM of two denominators is the smallest common denominator you can convert both fractions to before adding or subtracting them.

Math & Everyday

Least common multiple of two or more numbers, reduced step by step.

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Finds the least common multiple of two or more positive integers — the smallest number every value in your list divides into evenly.

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How to use it

Formula

LCM(a, b) = (a × b) ÷ GCD(a, b), where GCD comes from the Euclidean algorithm; for more than two numbers, reduce pairwise across the list.

Worked example

LCM(4, 6, 8): LCM(4,6) = 24÷2 = 12, then LCM(12,8) = 96÷4 = 24. So the LCM of 4, 6, and 8 is 24.

Recommendations

• Useful for adding fractions with different denominators — the LCM of the denominators is the smallest common denominator.
• For scheduling problems (e.g. two events repeating every 4 and 6 days), the LCM tells you when they next coincide.
• The LCM is always a multiple of every number in your list, and the GCD always divides every number — related but different.

Frequently asked questions

The LCM is the smallest common multiple; the GCD is the largest common divisor. For two numbers, LCM(a,b) × GCD(a,b) = a × b.