Factorial Calculator

What is a Factorial?

The factorial of a number (n!) is the product of all positive integers less than or equal to n. For example, 5! = 5 × 4 × 3 × 2 × 1 = 120.

How to Use This Calculator

Enter a non-negative integer and click "Calculate". The tool instantly computes the factorial and displays the result.

Factorial Formula

n! = n × (n-1) × (n-2) × ... × 2 × 1

By definition: 0! = 1

Where Factorials Are Used

• Permutations: Arranging objects in order
• Combinations: Selecting objects without order
• Probability: Calculating likelihoods
• Statistics: Advanced calculations

FAQ

What's the largest factorial I can calculate?
Our calculator handles factorials up to 170! (larger numbers use scientific notation).