Permutation Calculator
Calculate the exact number of possible ways you can arrange datasets. Input your Total Items (n) and the Amount Chosen (r) to simultaneously calculate both Permutations (nPr) and Combinations (nCr).
Last updated: February 24, 2026
Are you actually calculating combinations of identical outcomes over time? Try the Binomial Calculator
Experiment Parameters
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Permutations
Order MattersCombinations
Order IgnoresUnderstanding The Math
Permutations define all unique ordered sequences. Because the order of elements is strictly enforced, choosing the items A-B-C is counted as entirely distinct from C-B-A.
Without Repetition: P(n,r) = n! / (n-r)!
With Repetition: n^r
Combinations define group selections where the sequence is irrelevant. Here, choosing A-B-C is considered the exact same group as C-B-A. Because of this structural reduction, Combinations are always drastically smaller than Permutations.
Without Repetition: C(n,r) = n! / (r! * (n-r)!)
With Repetition: C(n+r-1, r)
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