GCF (HCF) of 18 and 12

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What is the Greatest Common Divisor of 18 and 12?

Answer

GCF (HCF) of 18 and 12 is
6

Common factors: 1, 2, 3, 6

6 divides both: 18 ÷ 6 = 3, 12 ÷ 6 = 2 — and 3 and 2 share no factor but 1, so no larger number divides both.

18 = 2 × 32

12 = 22 × 3

Prime1812Lowest power
22222
33233

GCF = 2 × 3 = 6

See Also

FAQ

What is the Greatest Common Divisor of 18 and 12?

GCF (HCF) of 18 and 12 is 6

How to find the GCF of 18 and 12?

You can find the GCF of 18 and 12 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 18 and 12 is 6.

What prime factors do 18 and 12 share?

The prime factorizations of 18 and 12 have 2 × 3 in common, and multiplying those shared primes gives 6 — exactly the greatest common factor.

How does the GCF reduce the fraction 18/12?

Divide the numerator and the denominator by the GCF 6: 18 ÷ 6 = 3 and 12 ÷ 6 = 2. So 18/12 in lowest terms is 3/2.