Summary
Calculate permutations nPr or combinations nCr.
Calculation details
Requires integers with 0 ≤ r ≤ n. Calculations retain raw JavaScript number precision; display values are rounded to at most six decimal places.
Formula
nPr = n!/(n−r)!; nCr = n!/(r!(n−r)!).
Worked example
Permutation Combination Calculator example
5C2 = 10.
How it works
Enter n and r as integers with 0 ≤ r ≤ n, then choose permutations or combinations.
Frequently asked questions
How accurate is the Permutation Combination Calculator?
The calculation keeps raw numeric precision and rounds only the displayed result to at most six decimal places.
What should I do with an invalid result?
Check that every visible value is finite and that no required divisor is zero.