Permutations Calculator
Calculate the number of permutations for selecting r items from a set of n using the nPr formula, free in your browser.
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How to use this calculator
- Enter the total items (n) and chosen (r).
- Press Calculate.
How it works
Permutations (nPr) count ordered arrangements: n! ÷ (n − r)!.
Worked example
5P2. = 20.
Common mistakes
- Using permutations when order doesn't matter — that's a combination instead.
- Forgetting that nPr requires r ≤ n.
Frequently asked questions
What is a permutation?
An ordered arrangement. The number of ways to arrange r items from n is nPr = n! ÷ (n − r)!.
How is a permutation different from a combination?
Permutations count order (AB and BA are different); combinations don't (AB and BA are the same).
When do I use permutations instead of combinations?
Use permutations when order matters (like first/second/third place); use combinations when it doesn't (like a lottery draw).
Related tools
- Combinations Calculator
- Factorial Calculator
- Permutations with Repetition Calculator
- Combinations with Repetition Calculator
- Arithmetic Sequence Calculator
- Average (Mean) Calculator
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Cite this tool
Zerdly. (2026). Permutations Calculator. Retrieved from https://www.zerdly.com/tools/permutations-calculator/
Tip: Enter any known values to calculate the remaining results.
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