ToolsXpo

Factorial Calculator

Instantly calculate the factorial (n!) of an integer.

This tool has an API.Automate it from your code — 1 credit/call.Open in Playground
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Examples & Use Cases

Input Integer (n)

5

Factorial Output (n!)

{ "input": 5, "factorial": 120, "scientific": "1.2e+2" }

What is a Factorial?

In mathematics, the factorial of a non-negative integer `n`, denoted by `n!`, is the product of all positive integers less than or equal to `n`. For example, `5! = 5 x 4 x 3 x 2 x 1 = 120`. Factorials are used extensively in statistics, combinatorics, and probability calculations.

About Factorial Calculator

Instantly calculate the factorial (n!) of an integer. It's built for calculations and quantitative checks, runs instantly, and works on any device — no install, no sign-up.

How to use Factorial Calculator

  1. Paste or type your input into the editor on the left.
  2. Leave the defaults, or tweak them if the tool exposes options.
  3. The result appears instantly on the right — everything runs in your browser, so nothing is uploaded.
  4. Copy the output, or download it, and you're done.

Why use Factorial Calculator?

  • Fast and local — the transform happens in your browser, so there's no round-trip and no waiting.
  • Private by default — your input never leaves your device.
  • Accurate — the same, well-tested logic powers both this page and the public API.
  • Free — unlimited use in the browser, with an optional API for automation.

Use it from the API

Everything this page does is also available as a REST endpoint, so you can call Factorial Calculator from your own code, a script or a CI pipeline.

Bash
curl "https://api.toolsxpo.com/v1/factorial-calculator" \
  -H "Authorization: Bearer txp_live_YOUR_KEY"

The endpoint returns a JSON envelope ({ ok, data, meta }) and costs 1 credit per successful call. Try it in the playground or browse the full API reference.

Frequently asked questions

Is Factorial Calculator free to use? Yes — use it in the browser as much as you like. The optional API has a free tier and pay-as-you-go pricing for heavy or automated use.

Is my data private? Yes. Factorial Calculator runs entirely in your browser — your input never leaves your device and nothing is logged or stored.

Can I automate Factorial Calculator? Yes — call the factorial-calculator API endpoint from any language and script it into your workflow.

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