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GCF for 12, 18 and 24

"Greatest Common Factor of 3 Numbers" Calculator

What's the Greatest Common Factor (GCF) of 12, 18 and 24?

Answer

GCF of 12, 18 and 24 is

(Six)

6 is the largest positive integer that divides 12, 18 and 24 without a remainder — every other common divisor of the three divides it too.

Finding the GCF of 12, 18 and 24 by Prime Factorization

Split all three numbers into prime factors, then keep every prime that appears in all three of them, each taken as many times as it appears in the poorest factorization. Multiplying what is left gives the greatest common factor:

All Prime Factors of 12: 2 × 2 × 3 (exponent form: 2² × 3)

All Prime Factors of 18: 2 × 3 × 3 (exponent form: 2 × 3²)

All Prime Factors of 24: 2 × 2 × 2 × 3 (exponent form: 2³ × 3)

Prime factor	12	18	24	Lowest power
2	2²	2	2³	2
3	3	3²	3	3

GCF = 2 × 3 = 6

Checking the GCF of 12, 18 and 24 Two Numbers at a Time

The greatest common factor is associative, so three numbers can be handled as two pairs — and this is what makes the Euclidean algorithm usable here: run it on the first pair, then run it again on that result and the third number.

GCF(a, b, c) = GCF(GCF(a, b), c)

GCF(12, 18) = 6

GCF(6, 24) = 6

GCF(12, 18, 24) = 6

The answer checks out by division — all three quotients come out whole:

12 ÷ 6 = 2

18 ÷ 6 = 3

24 ÷ 6 = 4

2, 3 and 4 have no common factor left — that is what makes 6 the greatest one.

Found an error in the calculation or the information?

Related Calculations

GCF Table

Number 1	Number 2	Number 3	GCF
9	12	18	3
10	12	18	2
11	12	18	1
12	12	18	6
12	13	18	1
12	14	18	2
12	15	18	3
12	16	18	2
12	17	18	1
12	18	18	6
12	18	19	1
12	18	20	2
12	18	21	3
12	18	22	2
12	18	23	1
12	18	24	6
12	18	25	1
12	18	26	2
12	18	27	3
12	18	28	2
12	18	29	1
12	18	30	6
12	18	31	1
12	18	32	2
12	18	33	3
12	18	34	2
12	18	35	1
12	18	36	6
12	18	37	1
12	18	38	2

About "Greatest Common Factor of 3 Numbers" Calculator

This calculator finds the Greatest Common Factor (GCF) of three numbers at once, without doing it in two passes. For example, it can help you find out what's the Greatest Common Factor (GCF) of 12, 18 and 24? (The answer is: 6). Enter the first number (e.g. '12'), the second (e.g. '18') and the third (e.g. '24'), then hit the 'Calculate' button.

The Greatest Common Factor of three numbers — also called the greatest common divisor (GCD) or highest common factor (HCF) — is the largest positive integer that divides all three of them with zero remainder

"Greatest Common Factor of 3 Numbers" Calculator

FAQ

What's the Greatest Common Factor (GCF) of 12, 18 and 24?

GCF of 12, 18 and 24 is 6

What prime factors do 12, 18 and 24 share?

All three factorizations contain 2 × 3, and multiplying those shared primes gives 6 — exactly the greatest common factor.

Can you get the GCF of 12, 18 and 24 two numbers at a time?

Yes, and it is the check this page prints. The GCF of 12 and 18 is 6, and the GCF of 6 and 24 is 6 — the same answer, because the greatest common factor is associative and does not depend on the order of the three numbers.

How does the GCF simplify the ratio 12 : 18 : 24?

Divide every term by the GCF 6: 12 ÷ 6 = 2, 18 ÷ 6 = 3 and 24 ÷ 6 = 4. So 12 : 18 : 24 in lowest terms is 2 : 3 : 4, and no whole number other than 1 divides all three of those.

GCF for 12, 18 and 24

What's the Greatest Common Factor (GCF) of 12, 18 and 24?

Finding the GCF of 12, 18 and 24 by Prime Factorization

Checking the GCF of 12, 18 and 24 Two Numbers at a Time

Related Calculations

See Also

GCF Table

About "Greatest Common Factor of 3 Numbers" Calculator

FAQ

What's the Greatest Common Factor (GCF) of 12, 18 and 24?

What prime factors do 12, 18 and 24 share?

Can you get the GCF of 12, 18 and 24 two numbers at a time?

How does the GCF simplify the ratio 12 : 18 : 24?

See Also

Number 1	Number 2	Number 3	GCF
9	12	18	3
10	12	18	2
11	12	18	1
12	12	18	6
12	13	18	1
12	14	18	2
12	15	18	3
12	16	18	2
12	17	18	1
12	18	18	6
12	18	19	1
12	18	20	2
12	18	21	3
12	18	22	2
12	18	23	1
12	18	24	6
12	18	25	1
12	18	26	2
12	18	27	3
12	18	28	2
12	18	29	1
12	18	30	6
12	18	31	1
12	18	32	2
12	18	33	3
12	18	34	2
12	18	35	1
12	18	36	6
12	18	37	1
12	18	38	2

Number 1	Number 2	Number 3	GCF
9	12	18	3
10	12	18	2
11	12	18	1
12	12	18	6
12	13	18	1
12	14	18	2
12	15	18	3
12	16	18	2
12	17	18	1
12	18	18	6
12	18	19	1
12	18	20	2
12	18	21	3
12	18	22	2
12	18	23	1
12	18	24	6
12	18	25	1
12	18	26	2
12	18	27	3
12	18	28	2
12	18	29	1
12	18	30	6
12	18	31	1
12	18	32	2
12	18	33	3
12	18	34	2
12	18	35	1
12	18	36	6
12	18	37	1
12	18	38	2

Number 1	Number 2	Number 3	GCF
9	12	18	3
10	12	18	2
11	12	18	1
12	12	18	6
12	13	18	1
12	14	18	2
12	15	18	3
12	16	18	2
12	17	18	1
12	18	18	6
12	18	19	1
12	18	20	2
12	18	21	3
12	18	22	2
12	18	23	1
12	18	24	6
12	18	25	1
12	18	26	2
12	18	27	3
12	18	28	2
12	18	29	1
12	18	30	6
12	18	31	1
12	18	32	2
12	18	33	3
12	18	34	2
12	18	35	1
12	18	36	6
12	18	37	1
12	18	38	2