How to Calculate Permutations
Calculate ordered arrangements of r items from n items.
The Formula
P(n,r) = n! / (n-r)!The permutations formula uses the mathematical relationship: P(n,r) = n! / (n-r)!. Each variable in the formula represents a measurable quantity that affects the final result.
Step-by-Step Method
- 1Identify all input values needed for the permutations calculation.
- 2Substitute your known values into the formula: P(n,r) = n! / (n-r)!.
- 3Perform the arithmetic operations in the correct order (PEMDAS/BODMAS).
- 4Check that your result has the correct units and is within a reasonable range.
- 5Verify using the interactive Permutations Calculator to confirm your answer.
Related Topics
permutationsarrangementscombinatorics
Use the Interactive Calculator
Skip the manual math — get instant results with our free Permutations calculator.