Factorial Calculator — Calculate n!

Calculator

A factorial calculator finds n!, the product of all positive integers from n down to 1.

What is it

Factorial is a multiplication operation used in permutations, combinations, and probability. For example, 5! is 5×4×3×2×1, which equals 120.

n! = n × (n-1) × ... × 2 × 1, 0! = 1

How to use

  1. 1Enter an integer from 0 to 170.
  2. 2Press calculate.
  3. 3Check the n! result.

Reference

Factorial Calculator — Calculate n! Reference
nn!
01
5120
103628800

Sources & standards

FAQ

What is 5!?

5! = 5×4×3×2×1 = 120.

Why is the range limited to 170?

The tool limits input to integers from 0 to 170 so the result stays within practical browser number display limits.

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