Factorial Calculator
n! and related combinatorics.
Enter your values
Enter the n you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- 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
At a glance
| What it does | n! and related combinatorics. |
|---|---|
| Category | Math |
| Inputs needed | n |
| Main output | 10! |
| Formula | n! = n × (n−1) × … × 1 |
| Cost | Free — no sign-up, no download |
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.
Inputs explained
- n
- Enter the n you are working with.
Worked example
Using the values the calculator loads with:
Inputs
- n10
Results
- 10!3,628,800
- Digits7
- (n−1)!362,880
- Scientific notation3.628800e+6
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.
What do I need to enter into the Factorial Calculator?
Just 1 value: n. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Factorial Calculator work out the answer?
n factorial is the product of all whole numbers from 1 to n, and 0! is defined as 1. It applies the formula n! = n × (n−1) × … × 1 and shows the working so you can check each step by hand.
Is the Factorial Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.