Find the greatest common factor (GCF) of two numbers with this greatest common factor calculator.

### What is the Greatest Common Factor?

The greatest common factor between two numbers is the largest

factor that both numbers are divisible by. Sometimes the greatest

common factor is also referred to as the greatest common divisor (gcd),

or the highest common factor (hcf).

For example, find the GCF of the two numbers 12 and 16:

The factors for 12 are 1, 2, 3, 4, 6 and 12. These are factors of 12 because

12 is divisible by all of these numbers.

The factors for 16 are 1, 2, 4, 8, 16.

The two numbers (12 and 16) share common factors (1, 2, 4).

The greatest of these is 4 and that is the greatest common factor.

### How to use the Greatest Common Factor Calculator

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