Factorial Calculator
Calculate the exact factorial of any whole number up to 5000, with the full number of digits.
How to use it
- Enter a whole number Any integer from 0 to 5000.
- Read the factorial The exact value of n! is shown in full.
- Note the digit count Useful for very large results.
Examples
| 5! | 120 |
|---|---|
| 10! | 3,628,800 |
About this tool
A factorial multiplies together every whole number up to n, and the result grows astonishingly fast — 20! is already over two quintillion. This calculator computes the exact value using big-integer arithmetic, so there’s no rounding even for huge inputs.
Factorials are central to counting problems, permutations and combinations, and probability. Alongside the full number, the tool reports how many digits it has, so you can appreciate just how quickly factorials explode. It all runs in your browser.
Frequently asked questions
How large a factorial can it compute?
Up to 5000!, computed exactly with big-integer arithmetic. The result can be thousands of digits long, so it's shown in full.
What is a factorial?
The factorial of n, written n!, is the product of all whole numbers from 1 to n. By definition, 0! equals 1.
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Updated June 14, 2026