6 min read
2026-01-20
A tool for computing factorials, permutations, combinations, and arrangements. Supports working with large numbers.
Factorial (n!) — the product of all natural numbers from 1 to n
Permutations (P) — the number of ways to arrange n elements in a row
Combinations (C) — the number of ways to choose k elements from n without regard to order
Arrangements (A) — the number of ways to choose k elements from n with regard to order
| Operation | Formula |
|---|---|
| Factorial | n! = 1 × 2 × 3 × ... × n |
| Combinations | C(n,k) = n! / (k! × (n-k)!) |
| Arrangements | A(n,k) = n! / (n-k)! |
| Permutations | P(n) = n! |
Select the type of calculation from the list
Enter the values of n and k (if required)
Click "Calculate"
Get the result with intermediate calculations
Factorials grow rapidly: 20! already exceeds 2 quintillion. The calculator supports computations up to 170!, after which the number exceeds the standard representation limit.
See also: Prime Number Checker, GCD and LCM, Statistics