GCF and LCM of 18 and 24
The greatest common factor and least common multiple of 18 and 24.
GCF of 18 and 24
6
LCM of 18 and 24
72
How it works
Break each number into its prime factors:
- 18 = 2 × 3²
- 24 = 2³ × 3
The GCF (6) multiplies the primes both share, at the lowest power each appears. The LCM (72) multiplies every prime that appears in either number, at the highest power — which is also 18 × 24 ÷ 6 = 72.
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Frequently asked questions
What is the GCF of 18 and 24?+
The greatest common factor (GCF) of 18 and 24 is 6 — the largest number that divides both 18 and 24 with no remainder.
What is the LCM of 18 and 24?+
The least common multiple (LCM) of 18 and 24 is 72 — the smallest number that both 18 and 24 divide into. It equals 18 × 24 ÷ GCF = 432 ÷ 6 = 72.