Combination & Permutation Calculator
Compute nCr and nPr exactly using big-integer arithmetic.
Combinations (nCr)
120
Permutations (nPr)
720
Enter n and r to get the number of combinations (nCr) and permutations (nPr). Uses BigInt for exact large counts.
How to use
- Enter the total number of items n.
- Enter how many you choose, r.
- Read the exact nCr and nPr counts and copy them.
Frequently asked questions
- What is the difference between nCr and nPr?
- nPr counts ordered arrangements of r items from n, while nCr counts unordered selections. nCr equals nPr divided by r!.
- Why use big integers?
- Combination and permutation counts grow very fast, so BigInt keeps results exact without floating-point rounding.