Common Factors Calculator

Find all common factors of two numbers.

How It Works

Enter two positive integers. The tool finds their GCD, then lists all factors of that GCD, which are exactly the common factors of both numbers.

Formula

Common factors of A and B = factors of GCD(A, B).

Frequently Asked Questions

What are the common factors of 12 and 18?

GCD(12,18)=6. Factors of 6: 1, 2, 3, 6. So common factors are 1, 2, 3, 6.

Do coprime numbers have common factors?

Coprime numbers have only 1 as a common factor.