GCD/LCM Calculator

Find the Greatest Common Divisor (GCD) and Least Common Multiple (LCM) of two or more numbers.

▼ Enter numbers separated by commas, then click Calculate
Result
GCD (Greatest Common Divisor)
LCM (Least Common Multiple)

Finding GCD and LCM

This tool finds both the Greatest Common Divisor (GCD) — the largest number that divides evenly into all your numbers — and the Least Common Multiple (LCM) — the smallest number all your numbers divide into evenly. Enter any list of comma-separated numbers to calculate both at once.

Example: for 12, 18, 24, the GCD is 6 (the largest shared factor) and the LCM is 72 (the smallest number all three divide into evenly).

GCD and LCM Explained

The Greatest Common Divisor (GCD) is the largest number that divides evenly into all given numbers. The Least Common Multiple (LCM) is the smallest number that all given numbers divide into evenly. Both are computed using the Euclidean algorithm.

Frequently Asked Questions

The GCD is the largest number that divides evenly into all given numbers.

The LCM is the smallest number that all given numbers divide into evenly.

Both the GCD and LCM are computed using the Euclidean algorithm.

Yes — enter as many numbers as you need, and the calculator finds the GCD and LCM across the entire set at once, not just pairs.

GCD is commonly used to simplify fractions, while LCM is used to find common denominators and solve problems involving repeating cycles or schedules.

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