Quick start
- Enter n, the total number of items.
- Enter r, the number of items selected.
- Press Calculate nPr and nCr.
- Use the permutation answer when order matters and the combination answer when order does not matter.
Permutation vs combination
A permutation counts arrangements, so ABC and BAC are different outcomes. Use nPr when the order matters.
A combination counts groups, so ABC and BAC are the same group. Use nCr when the order does not matter.
Using counting in probability
Many probability problems compare favorable outcomes with total possible outcomes.
Permutations and combinations help count those outcomes without listing every case one by one.
Examples from the calculator
720 permutations, 120 combinations
2,598,960 combinations
336 permutations
History, privacy, and copying
Recent answers stay visible in the page while you work. The history is kept only in the current browser tab and is not sent to a server.
Copy answer copies the expression and result so you can paste it into notes, homework, a message, or another document.