statistics

Permutations & Combinations Calculator

Enter n and r to get the number of permutations, combinations and the factorial of n.

  • 20Permutations (nPr)
  • 10Combinations (nCr)
  • 120n! (factorial)

How to use it

  1. Enter n The total number of items.
  2. Enter r How many you choose.
  3. Read the results Permutations, combinations and n! update instantly.

Examples

nPr(5, 2) 20
nCr(52, 5) 2,598,960

About this tool

Permutations and combinations count the number of ways to arrange or choose items. Use permutations (nPr) when the order matters, like a race finishing order, and combinations (nCr) when it does not, like a lottery draw or a committee.

This calculator gives both, plus the factorial of n, computed exactly for the ranges that fit standard numbers. Everything runs in your browser.

Frequently asked questions

What's the difference between a permutation and a combination?

Permutations count arrangements where order matters; combinations count selections where order does not. There are always at least as many permutations as combinations.

When would I use nCr?

For things like lottery draws or choosing a committee, where the order of selection doesn't matter. Picking 6 from 49 gives 13,983,816 combinations.

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Updated June 12, 2026