# GCF and LCM Calculator

The GCF and LCM calculator (also called the GCF finder) will determine the greatest common factor and least common multiple of a set of two to six numbers. You can also compute the GCF and LCM by hand or use the GCF calculator or the LCM calculator to find more detailed methods to compute these problems by hand.

If you want to find the GCF and LCM, first you need to get the prime factorization of each number in the set. This is done easily with the prime factorization calculator.

## How to Use the GCF Finder

Suppose you want to find the GCF and LCM of `24`

and `56`

.

- First we get the prime factorizations of
`24 = 2 * 2 * 2 * 3`

and`56 = 2 * 2 * 2 * 7`

. - The greatest common factor is what is present in both sets of factors, which is
`2 * 2 * 2 = 8`

. - The least common multiple is the highest power of all exponents, which is
`2 * 2 * 2 * 3 * 7 = 168`

.

There are several methods for finding GCF, including prime factorization or Euclidean algorithm using the modulo operation. The factor calculator is also a handy tool for finding GCF and LCM. Note that while finding the GCF and LCM of smaller numbers is relatively simple by hand, the GCF and LCM calculator is quicker and much easier for larger or larger sets of numbers.