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GCD & LCM Calculator

Find the Greatest Common Divisor and Least Common Multiple of a set of numbers.

Enter Numbers
Least Common Multiple (LCM)
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Greatest Common Divisor (GCD)
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Understanding GCD & LCM

GCD

The Greatest Common Divisor is the largest positive integer that divides two or more numbers without leaving a remainder.

Example: GCD of 12 and 18.

Factors of 12: 1, 2, 3, 4, 6, 12.

Factors of 18: 1, 2, 3, 6, 9, 18.

Common largest factor is 6.

LCM

The Least Common Multiple is the smallest positive integer that is divisible by two or more numbers.

Example: LCM of 4 and 6.

Multiples of 4: 4, 8, 12, 16...

Multiples of 6: 6, 12, 18...

Smallest common multiple is 12.

LCM(a,b) = (a × b) / GCD(a,b)