How to Use Permutation Calculator
The Permutation Calculator needs two values: the total number of distinct items n and the number chosen r. Enter non-negative integers with r less than or equal to n. The Permutation Calculator validates the inputs and returns the ordered arrangement count.
Formula & Theory — Permutation Calculator
The Permutation Calculator uses the permutation formula:
P(n, r) = n! / (n - r)!
Because order matters, choosing A then B is different from choosing B then A. This is the main difference between a permutation and a combination. The Permutation Calculator shows the factorial substitution so the result is traceable.
Use Cases for Permutation Calculator
Use the Permutation Calculator for probability homework, ranking problems, password arrangements, race placements, schedules, and ordered selections. It is especially helpful when the same selected items can appear in different orders.