Factorial Calculator
n! and related combinatorics.
Enter your values
Results update instantly as you type — no submit needed.
Results
- 10!
- 3,628,800
- Digits
- 7
- (n−1)!
- 362,880
- Scientific notation
- 3.628800e+6
Quick answer
n factorial is the product of all whole numbers from 1 to n, and 0! is defined as 1.
n! = n × (n−1) × … × 1
How to use the Factorial Calculator
- 1Enter a whole number between 0 and 170.
- 2Read the factorial and its digit count.
- 3Use permutation or combination tools for arrangements.
Frequently asked questions
Why is 0! = 1?
There is exactly one way to arrange nothing, and it keeps combinatorics formulas consistent.
Why cap at 170?
171! exceeds the largest number JavaScript can represent.