Calculate permutations (nPr), combinations (nCr), and factorials instantly.
Enter the total number of items (n) and how many items are being chosen (r). The calculator instantly shows the factorial, permutations, and combinations.
Permutation (nPr) counts arrangements where order matters. Combination (nCr) counts selections where order does not matter.
nPr = n! ÷ (n−r)!
nCr = n! ÷ (r! × (n−r)!)