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n!

Factorial Calculator

Calculate n factorial

factorialn!

📖 How to Use

  1. Enter a non-negative integer n (0–170)
  2. Click Calculate n! to see the result

📐 Formula

n! = n × (n−1) × (n−2) × ... × 2 × 1
0! = 1 (by definition)

❓ FAQ

What is 0 factorial?▾
0! = 1. This is a mathematical convention.
What's the largest factorial I can calculate?▾
Up to 170! — beyond that the result overflows.

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About Factorial Calculator

This tool is completely free, no registration required. Works directly in your browser. Supports both PC and mobile devices.

Factorial Calculator is a free online tool that works on both PC and mobile. No registration or download required — just open in your browser. Results are accurate and reliable for everyday use and professional reference.