GCF & LCM calculator

Find the greatest common factor or least common multiple of two or more numbers.

Numbers

GCF (Greatest Common Factor)

The largest number that divides both numbers evenly. GCF(24,36) = 12.

LCM (Least Common Multiple)

The smallest number both divide into. LCM(24,36) = 72.

Relationship

GCF(a,b) × LCM(a,b) = a × b. So LCM = (a×b)/GCF.

Methods

Prime factorization: GCF uses minimum powers, LCM uses maximum powers. Euclidean algorithm: GCF(a,b) = GCF(b, a mod b).

Popular GCF & LCM problems
GCF(24, 36) GCF(12, 18) GCF(48, 64) GCF(100, 75) LCM(12, 18) LCM(8, 14) GCF(56, 84) LCM(15, 20) GCF(72, 96) LCM(24, 36)
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