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.

Combination Formula

Following is the combination formula on how to calculate combination.
C(n,r) = n!/(r!(n−r)!), where
n! = n*(n-1)!

For example, to calculate C(5,3), we would plugin the numbers to the combination formula
5!/(3!)(5-3)! = (5*4*3*2*1)/3!(2!) = (120)/(3*2*1)*(2*1) = 10