Factorial calculator

Enter an integer and calculate its factorial (n!), the product of all integers from 1 to n.

What is a factorial

The factorial of n (written n!) is the product of all integers from 1 to n. For example 5! = 5×4×3×2×1 = 120. It's used in combinatorics and probability.

Note

The calculation uses arbitrary-precision integers: even very large factorials are exact.