Free Combination Calculator

Calculate the number of combinations (unordered selections) of n items taken r at a time. Uses the formula C(n,r) = n! / (r! × (n-r)!).

Combinations

120

Permutations720

How to Calculate Combinations

Formula

C(n, r) = n! / (r! × (n - r)!)

Where:

  • n = total number of items
  • r = number of items being chosen
  • Combinations count selections where order does not matter.

    Example Calculation

    How many ways can you choose 3 items from a set of 10? (Order does not matter)

    1. 01C(10, 3) = 10! / (3! × 7!)
    2. 02= 3,628,800 / (6 × 5,040)
    3. 03= 3,628,800 / 30,240
    4. 04= 120

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