Online Calculators > Math Calculators > Combination Calculator
Combination Calculator
Combination Calculator  calculate combination which is how many different ways to choose items where order doesn't matter. Online combination calculator to find number of ways to select r out of n items regardless of the order.
Total # of Items (n) must be greater or equal to the # of Items Chosen (r).
Combination Formula
Following is the combination formula on how to calculate combination.
C(n,r) = n!/(r!(n−r)!), where
n! = n*(n1)!
For example, to calculate C(5,3), we would plugin the numbers to the combination formula
5!/(3!)(53)! = (5*4*3*2*1)/3!(2!) = (120)/(3*2*1)*(2*1) = 10
1 combination 0
2 combination 1
3 combination 2
4 combination 2
5 combination 3
6 combination 4
8 combination 1
9 combination 2
10 combination 4
12 combination 4
20 combination 2
30 combination 4
