About this calculator
Does order matter?
- Permutations (nPr) count arrangements where order matters: a president, vice president, and treasurer chosen from a club, or the first three finishers in a race.
- Combinations (nCr) count selections where order doesn't matter: a 3-person committee, or a hand of cards.
The number of combinations is always smaller (or equal) because each group of r items can be arranged r! ways. Combinations also appear in the binomial probability formula.