math calculator

Least Common Multiple (LCM) Calculator

Find the smallest number that is a multiple of both inputs.

Important Use Notice

Informational calculator only. Verify important outputs independently before legal, tax, medical, engineering, safety-critical, contractual, employment, or compliance use.

Estimate

Enter job values, review the estimate, then use the decision hints before ordering or quoting.

First positive integer

Second positive integer

Estimate Results

Enter values to see the result.

Example

LCM(6, 8) = 24

Formula

LCM(a, b) = |a × b| / GCD(a, b)

Uses Euclidean algorithm to find GCD, then divides product by GCD. Efficient and exact.

For multiple numbers: LCM(a,b,c) = LCM(LCM(a,b), c)

Check

Confusing LCM with GCF (LCM is larger)
Confirm that all inputs use the same unit system expected by the formula.

Next Step

FAQ

How is LCM related to GCF?

GCF(a,b) × LCM(a,b) = |a × b|. They are dual concepts.

Why is LCM for fractions?

Common denominator = LCM of denominators — makes addition/subtraction easy.