Factorial Calculator
Factorials grow fast — 20! already has 19 digits. Enter any whole number from 0 to 170 and this tool shows the full multiplication chain, n × (n-1) × ... × 1, plus the exact result — handy for probability, combinatorics and homework.
How to use
- Enter a whole number between 0 and 170.
- See the expansion (n x (n-1) x ... x 1) and the final result.
- For 0, the tool shows 0! = 1, which is the standard definition in combinatorics.
- Use the result in probability questions like permutations and combinations.
Note: 0! = 1 by definition. Factorials larger than 170 go beyond the normal number range, so the limit is 170.