Permutation and Combination Calculator
Enter whole numbers n and r to calculate exact factorial, permutation, and combination values. This is a mathematical calculator, not a prediction or betting tool.
A QUICK WALKTHROUGH
How to use this tool
- Enter n from 0 through 170 and r from 0 through n.
- Choose Calculate.
- Read the exact integer results; values are limited to keep the browser responsive.
Defined inputs
n is 0–170 and r is 0–n. Factorials and results are exact within the safe integer display limit.
Local calculation
All arithmetic runs in your browser. No prediction, odds, or gambling advice is produced.
GOOD TO KNOW
Common questions
What is nPr?
nPr = n!/(n-r)!, the number of ordered selections.
What is nCr?
nCr = n!/(r!(n-r)!), the number of unordered selections.
Can r be greater than n?
No. The tool rejects r > n.