Combination Calculator
Enter integers n and r within the stated bounds to count selections where order does not matter.
A QUICK WALKTHROUGH
How to use this tool
- Enter integers n and r within the stated bounds.
- Choose Calculate.
- Review nCr and its exact integer result.
Input limits
Only integers with 0 ≤ r ≤ n ≤ 170 are accepted. Calculation runs in the browser and does not predict odds.
GOOD TO KNOW
Common questions
What is nCr?
nCr = n!/(r!(n-r)!), the number of unordered selections.
Are values uploaded?
No, arithmetic is local.