Permutation and Combination Calculator

Permutations vs. Combinations

Both count the ways to choose r items out of n, but they differ on whether order matters. A permutation counts arrangements where order matters (like ranking 1st, 2nd, 3rd place). A combination counts selections where order doesn't matter (like choosing 3 people for a committee) - so it will always be a smaller number than the permutation for the same n and r.

n! means n factorial: n × (n−1) × (n−2) × ... × 1