Permutations and Combinations Table

A permutation counts the number of ways to arrange r items chosen from n, where order matters. A combination counts the same selection without regard to order. This page provides quick-lookup tables for both, plus a calculator for any n and r.

Permutations & Combinations Calculator

Enter n (total items) and r (items chosen) to find nPr and nCr.

P(10, 3)720
C(10, 3)120

Formulas

Both formulas build on the factorial:

  • Permutations: P(n, r) = n! / (n − r)!
  • Combinations: C(n, r) = n! / (r! (n − r)!) = P(n, r) / r!

Permutations Table — P(n, r)

Number of ordered arrangements of r items chosen from n. A dash (—) means r > n, which is not possible.

nr=0r=1r=2r=3r=4r=5
01—————
111————
2122———
31366——
414122424—
5152060120120
61630120360720
717422108402,520
818563361,6806,720
919725043,02415,120
10110907205,04030,240

Combinations Table — C(n, r)

Number of unordered selections of r items chosen from n. These are the same values as the binomial coefficients in Pascal's Triangle, which has the full triangle for higher rows.

nr=0r=1r=2r=3r=4r=5
01—————
111————
2121———
31331——
414641—
515101051
6161520156
71721353521
81828567056
9193684126126
1011045120210252

Permutations vs. Combinations

  • Order matters → permutation: arranging 3 books on a shelf, assigning 1st/2nd/3rd place in a race, forming a PIN code.
  • Order doesn't matter → combination: choosing 3 toppings for a pizza, picking a 5-person committee, dealing a poker hand.
  • A so-called "combination lock" is actually a permutation, since the order of the numbers matters.

See also