Common Factor Calculator

List every factor that two or more whole numbers share, and their greatest common factor.

Whole numbers	24, 36

Whole numbers

Separate with commas or spaces.

Common factors

1, 2, 3, 4, 6, 12

24, 36 share 6 factors; the greatest is 12.

Number of common factors: 6
Greatest common factor: 12

Factors of each number

Number	Factors
24	1, 2, 3, 4, 6, 8, 12, 24
36	1, 2, 3, 4, 6, 9, 12, 18, 36

About the Common Factor Calculator

Enter two or more whole numbers, separated by commas. The calculator lists every common factor, the greatest common factor and how many there are.

Common factors are the numbers that divide every number in the set exactly. They are exactly the factors of the greatest common factor, so the calculator finds the GCF first and lists its factors.

The formula

Common factors of a, b = factors of GCF(a, b)

Worked example

24 and 36

GCF = 12
Factors of 12: 1, 2, 3, 4, 6, 12

Questions people ask

Is 1 always a common factor?

Yes, 1 divides every whole number.

What is a common factor used for?

Simplifying fractions and ratios, and splitting things into equal groups.

How do I find common factors quickly?

Find the GCF first; every factor of the GCF is a common factor.