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Permutation & Combination Calculator

Count how many ways to choose or arrange r items from a set of n — both nPr and nCr, with a short breakdown of why they differ.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

nPr = n! / (n − r)! (order matters). nCr = n! / (r! · (n − r)!) (order does not matter).

In depth

Count how many ways to choose or arrange r items from a set of n — both nPr and nCr, with a short breakdown of why they differ.