Runs locally
Combinations
C(n, k) without repetition.
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Exact integer combinations for n up to 1000.
About this tool
Find how many different groups of k items can be chosen from n, when order does not matter. For example, there are 13,983,816 ways to pick 6 numbers out of 49.
How to use it
- 01
Enter n, the total number of items.
- 02
Enter k, how many items are chosen.
- 03
Read the exact number of combinations.
FAQ
Frequently asked questions
What is the formula?
C(n, k) = n! / (k! × (n − k)!). The tool computes it with exact integer arithmetic.
How is it different from permutations?
Combinations ignore order: choosing A then B is the same as B then A.