Permutation and Combination Calculator

Enter n and r to find the number of permutations (nPr) and combinations (nCr), with the factorial working shown.
nPr and nCr
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How it works

nPr = n! / (n-r)!. nCr = n! / [r!(n-r)!].

Frequently Asked Questions

When do I use each?
Use permutations when order matters and combinations when it does not.