What is 0! (0 Factorial)?
0! (0 factorial) equals 1 by mathematical convention.
How to use this tool
- Enter n in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your n! and the full breakdown beneath it.
By definition, 0 factorial equals 1 — a common source of confusion that this calculator clears up.
Frequently asked questions
- What is a factorial?
- The factorial of n (written n!) is the product of all positive integers up to n. By definition, 0! = 1.