Statistics & Probability Calculators
Combination Calculator
Calculate nCr, the number of unordered selections of r items from n.
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What is Combination?
A combination is a selection where order does not matter: the number of r-item groups you can make from n. nCr = n! ÷ (r!(n − r)!) is the binomial coefficient that appears in the binomial distribution and in Pascal's triangle.
How it works
The multiplicative form multiplies and divides term by term, and because each intermediate product is divisible by its divisor the result stays exact without building three enormous factorials. That is what makes nCr for large n both correct and instant.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
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