Combination & Permutation Calculator
Count ways to choose r items from n — ordered (permutation) or unordered (combination).
Combination C(10,3)
120
n! / (r!(n−r)!)
Permutation P(10,3)
720
n! / (n−r)!
n! = 3,628,800
r! = 6
(n−r)! = 5,040
Combination: Order doesn't matter. Selecting a committee of 3 from 10 people → 120 ways
Permutation: Order matters. Arranging 3 items from 10 → 720 ways