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Factorial Calculator

Calculate the factorial of a number (n!). Supports large numbers.

Last updated: 2/3/2026

The factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n.

Calculator Inputs

Results

Enter values above to see your results

How It Works

Enter an integer. We multiply n × (n-1) × (n-2) ... × 1.

Worked Examples

Calculate 5!

Sequence:5 × 4 × 3 × 2 × 1= Multiply
Result:120= 120

Tips & Best Practices

  • 0! is defined as 1.
  • Factorials grow very quickly. 100! has 158 digits!

Frequently Asked Questions

What is 0! ?

By definition, 0! = 1.