GCF for 18 and 12

What is the Greatest common Divisor of 18 and 12?

Answer: GCF of 18 and 12 is 6

(Six)

Finding GCF for 18 and 12 using all factors (divisors) listing

The first method to find GCF for numbers 18 and 12 is to list all factors for both numbers and pick the highest common one:

All factors of 18: 1, 2, 3, 6, 9, 18

All factors of 12: 1, 2, 3, 4, 6, 12

So the Greatest Common Factor for 18 and 12 is 6

Finding GCF for 18 and 12 by Prime Factorization

The second method to find GCF for numbers 18 and 12 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 18: 2, 3, 3

All Prime Factors of 12: 2, 2, 3

As we can see there are Prime Factors common to both numbers: 2, 3

Now we need to multiply them to find GCF: 2 × 3 = 6

See Also

About "Greatest Common Factor" Calculator

This calculator will help you find the greatest common factor (GCF) of two numbers. For example, it can help you find out what is the Greatest common Divisor of 18 and 12? (The answer is: 6). Select the first number (e.g. '18') and the second number (e.g. '12'). After that hit the 'Calculate' button.
Greatest Common Factor (GCF) also known as the Greatest Common Divisor (GCD) or Highest Common Factor (HCF) - it is the largest positive integer that divides each of the integers with zero remainder

GCF Table

Number 1Number 2GCF
312
412
512
612
712
812
912
1012
1112
121212
13121
14122
1512
1612
17121
1812
19121
2012
21123
22122
23121
241212
25121
26122
27123
28124
29121
30126
31121
32124

FAQ

What is the Greatest common Divisor of 18 and 12?

GCF of 18 and 12 is 6