Exact nCr calculator

How many combinations are possible?

Use this when order does not matter. Choosing A then B is the same as choosing B then A.

C(n, r)120

C(10, 3) exact possibilities

The formula

C(n, r) = n! ÷ (r! × (n − r)!)

We calculate with arbitrary-precision integers, so large answers are not rounded.

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