Factorial Calculator
Find n! with the full multiplication expanded.
What is a factorial calculator?
A factorial calculator finds n!, which is n multiplied by every whole number below it. Example: 5! = 120.
How to use it
Enter a whole number from 0 to 20, then tap Calculate.
Formula
n! = n × (n – 1) × (n – 2) × … × 2 × 1. And 0! = 1 by definition.
Example
5! = 5 × 4 × 3 × 2 × 1 = 120. Factorials grow fast: 10! = 3,628,800.
Frequently Asked Questions
What is 5!?
120.
What is 0!?
1.
Can I find the factorial of a negative number?
No, factorial is not defined for negative numbers.
More calculators: Math Tools and All Tools.