Factorial Calculator
Calculate the factorial of any non-negative integer.
Factorial
3,628,800
Digit Distribution
Factorial Growth
Factorial
| n | n! | Digits |
|---|---|---|
| 0 | 1 | 1 |
| 1 | 1 | 1 |
| 2 | 2 | 1 |
| 3 | 6 | 1 |
| 4 | 24 | 2 |
| 5 | 120 | 3 |
| 6 | 720 | 3 |
| 7 | 5,040 | 4 |
| 8 | 40,320 | 5 |
| 9 | 362,880 | 6 |
| 10 | 3,628,800 | 7 |
Practical Example
n! = n × (n−1) × (n−2) × ... × 2 × 1. Special cases: 0! = 1, 1! = 1. Example: 5! = 5 × 4 × 3 × 2 × 1 = 120.
Frequently Asked Questions
What is a factorial?
A factorial (n!) is the product of all positive integers up to n — for example, 5! = 5 × 4 × 3 × 2 × 1 = 120.
What is 0 factorial?
0! is defined as 1 by convention because the empty product equals 1, and it makes formulas in combinatorics work cleanly.
Why do factorials grow so fast?
Each factorial multiplies by another integer, so values like 20! already exceed 2.4 quintillion.
What if I get a different answer when calculating manually?
First check your order of operations (PEMDAS/BODMAS), then verify your units are consistent. Common errors include rounding too early, sign mistakes, and incorrect formula application. Use this calculator to verify each step of your work.
Are there shortcuts or mental math tricks?
Yes! Many mathematical operations have estimation shortcuts. For example, squaring numbers ending in 5, using the distributive property, or applying benchmark fractions. While shortcuts help with estimates, always use exact calculations for important work.
Disclaimer: This calculator provides estimates for informational purposes only. Actual results may vary. Consult a qualified professional for personalized advice.