Factorial Calculator
Compute N! exactly, even for large N.
25! has
26digits15511210043330985984000000
Free online factorial calculator. Compute the factorial of any whole number exactly using big-integer arithmetic, with the full result and its digit count. Runs in your browser.
How to use the Factorial Calculator
- 01Enter a non-negative whole number N.
- 02N! is computed exactly, with no rounding.
- 03See the digit count and copy the full result.
Frequently asked questions
What is a factorial?
The factorial of N, written N!, is the product of all whole numbers from 1 to N. For example, 5! = 5 × 4 × 3 × 2 × 1 = 120. By definition 0! = 1.
How can it handle such large numbers?
It uses JavaScript BigInt arithmetic, so results are exact rather than rounded like normal floating-point numbers, even when they run to thousands of digits.