Calculate Combinations & Permutations
Total number of items
Number of items to select
How to Use
1
Select Mode
Choose Combination (order doesn't matter) or Permutation (order matters).
2
Enter Values
Input n (total items) and r (items to select).
3
Calculate
Get instant results with formula explanation.
Understanding Probability
Combination (nCr)
Number of ways to choose r items from n items where order doesn't matter.
nCr = n! / (r! × (n-r)!)
Permutation (nPr)
Number of ways to arrange r items from n items where order matters.
nPr = n! / (n-r)!