Permutation Calculator
Calculate Permutations
Compute permutations with and without repetition. Given n distinct items and r selected positions, permutations without repetition are nPr = n Ć (nā1) Ć ā¦ Ć (nār+1), and with repetition are n^r.
About Permutations
A permutation is an arrangement of items where order matters. When repetition is not allowed, the number of permutations is nPr. When repetition is allowed, each position can take any of the n items, giving n^r.
Formulas
- Without repetition: nPr = n Ć (nā1) Ć (nā2) Ć ā¦ Ć (nār+1) = n! / (nār)!
- With repetition: n^r
Use cases
- Passwords / PINs: Count the number of ordered codes
- Arrangements: Seating, lineups, schedule orders
- Sampling without replacement: Ordered selections