Skip to content
aletheiaAll tools

Math tool

Factorial Calculator

Multiply every whole number from 1 through n.

Free · Private · Runs in your browser

Counting and permutations

Calculate n factorial

Enter a nonnegative whole number up to 170. Factorial multiplies every whole number from 1 through n.

Your result will appear here after you submit a valid whole number.

Formula and method

For a whole number n, factorial is n! = n × (n − 1) × … × 2 × 1. The standard empty-product convention makes 0! equal to 1.

Boundaries

  • Only nonnegative whole numbers from 0 through 170 are accepted.
  • 170 is the largest supported input whose factorial remains finite in a JavaScript number.
  • Results are displayed as whole-number formatted values; very large values are subject to floating-point precision limits.

Version and verification

Calculation version 1.0.0; deterministic fixtures last verified 2026-08-20.