Permutations & Combinations Calculator
Calculate nPr (permutations) and nCr (combinations) for any n and r. Free and private, right in your browser.
Type in n (your total items) and r (how many you're choosing or arranging), and get both nPr and nCr instantly, handy for probability homework, lottery odds, tournament bracket counts, or figuring out how many passwords or seating arrangements are possible.
How to use it
- Enter your total number of items (n)
- Enter how many you're choosing or arranging (r)
- Read off the nPr and nCr results instantly
Frequently asked questions
- What's the difference between nPr and nCr?
- nPr (permutations) counts arrangements where order matters, like ranking 3 winners out of 10 racers. nCr (combinations) counts selections where order doesn't matter, like picking a 3-person committee out of 10 people.
- What happens if r is bigger than n?
- There are zero valid arrangements or selections, since you can't choose more items than exist in the set. The tool will show 0 rather than an error.
- Can it handle large numbers like 50 choose 25?
- Yes. It computes factorials using a method that avoids overflow for reasonably large n, so results like 50C25 (over 126 billion) come out exact rather than as an approximation.
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Nothing is uploaded
The file never leaves your device. There is no server to send it to, so there is nothing to leak, log, or subpoena.
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No signup, no limits
No account, no email, no daily cap, no watermark, and no paid tier waiting behind the third file.
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Works offline
Load the page once and it keeps working with the network off, because all the work was always happening locally.