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Combination calculator

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The calculator needs JavaScript. The tables below give the same numbers for common cases.

How it is worked out

  1. nCr = n! ÷ (r! × (n − r)!) = 10! ÷ (3! × 7!).
  2. Equivalent: nPr ÷ r! = 120.
Worked examples
InputsAnswer
n: 10; r: 3C(10, 3) = 120.
n: 52; r: 5C(52, 5) = 2,598,960.
n: 49; r: 6C(49, 6) = 13,983,816.

How to use it

A combination counts the ways to choose r items from n different items when order does not matter: nCr = n! ÷ (r! × (n − r)!). Choosing A and B is the same as choosing B and A.

For 10 items taken 3 at a time, 10C3 = 120. The number of 5-card hands from a 52-card deck is 52C5 = 2,598,960.

Frequently asked questions

What is 10C3?

120.

How many 5-card poker hands are there?

52C5 = 2,598,960.

How are nCr and nPr related?

nCr = nPr ÷ r!, because each group of r items can be ordered in r! ways.

Method: standard arithmetic shown step by step; no outside data is used. Checked 2026-11-12.

Written by Calculators Free Editorial Team · Data checked 2026-11-12
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General information only. Results are plain arithmetic on the numbers you enter; check anything important (money, health, school work) against your own records or the official source.