Permutation Calculator

Permutation Calculator lets you ordered selections equal n! / (n−r)!. Enter your own values or load the worked example.

Method and calculation

Ordered selections equal n! / (n−r)!.

Inputs and settings

Permutation Calculator accepts Total items (minimum 0, maximum 1000); Items selected (minimum 0, maximum 1000).

Worked example

Permutation Calculator example — Total items: 10; Items selected: 3. Computed output: { "permutations": "720" }

Output and limitations

Order matters when assigning a president, secretary and treasurer from a group. Selecting the same people for different offices counts as different arrangements. Repetition is not allowed, and exact integer arithmetic retains large factorial results without floating-point rounding.

Technical references: JavaScript numerical operations

Permutation Calculator FAQs

Permutation Calculator applies the following rule to your input: Ordered selections equal n! / (n−r)!. The worked example on this page uses the same processor as the result button.
Permutation Calculator has these boundaries: Use finite inputs. Results use double-precision arithmetic. Start by checking the total items field against the units or format shown.
Permutation Calculator provides this sample: { "permutations": "720" }. Use the sample button to reproduce it, then replace the inputs with your own values.