Calculate combinations, permutations, and factorial values with strict integer validation.
Enter integers with 0 less than or equal to r less than or equal to n less than or equal to 1000.
Combinations
C(10,3) = 120
Permutations
P(10,3) = 720
10!
3628800
3!
6
Combinations count ways to choose items where order does not matter. Permutations count ways to arrange items where order does matter.
C(n,r) = n! / (r!(n-r)!)
P(n,r) = n! / (n-r)!
Choose 6 from 49
C(49, 6) = 13,983,816
P(49, 6) is the matching permutation example for the same inputs.
For a separate quick check: P(8, 3) = 336.
Use combinations when order does not matter.
Use permutations when order matters.
No. In this calculator that is treated as invalid input.
It keeps counting formulas consistent.
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