Factorial (n!) Calculator
Use this free factorial calculator to compute n! (n factorial). Enter any non-negative integer and get your result instantly.
What Is a Factorial?
The factorial of a non-negative integer n is the product of all positive integers from
1 to n. It is written as n!.
Factorials are used in probability, statistics, combinatorics, and many areas of mathematics such as permutations and series expansions.
Factorial Formula
The factorial of a number n is defined as:
n! = n × (n − 1) × (n − 2) × ... × 3 × 2 × 1
Special case:
0! = 1
- n = any non-negative integer
- n! = factorial of n
Example Calculation
Example: Find the factorial of 5.
5! = 5 × 4 × 3 × 2 × 1 = 120
The factorial of 5 is 120.