Combinations Calculator
MATHEMATICS
Combinations Calculator
Count unordered selections without replacement.
UNDERSTAND YOUR RESULT
How it works
Count unordered selections without replacement.
THE CALCULATIONC(n, r) = n! / (r! × (n − r)!)
Using this calculator
Enter available items, unordered selections. C(n, r) = n! / (r! × (n − r)!).
What to keep in mind
Calculations use finite real numbers. Intermediate values are unrounded; very large or undefined results are rejected.
Frequently asked questions
Are my entries saved?
No. Calculator inputs remain in the current page and are cleared when you reload or leave. The tools do not upload your entries.
Why are results rounded?
The display is rounded for readability. Calculations use unrounded intermediate values. An estimate should not be interpreted as an exact measurement.