Lean Body Mass Calculator

LBM from Boer, James or Hume formulas.

100% private — no uploads Free & unlimited Read tutorial

See how it works

Watch a quick simulation of this tool in action — no file needed.

How to use Lean Body Mass Calculator

Follow these steps — everything happens instantly in your browser.

  1. 1

    Step 1. Pick your biological sex.

  2. 2

    Step 2. Enter your weight and height.

  3. 3

    Step 3. Choose a formula (Boer, James or Hume).

  4. 4

    Step 4. Read lean mass, fat mass and estimated body fat %.

Why use this tool

Private by design

All processing happens locally in your browser. Open DevTools → Network and you'll see zero file uploads. Ever.

Instant

No upload wait, no queue, no server round-trip. Results appear the moment you drop a file.

Free & unlimited

No accounts, no watermarks, no daily caps. Use it as many times as you like, forever.

Works everywhere

Desktop, tablet or phone — every tool is responsive and installable as a PWA for offline use.

Frequently asked questions

Everything you might want to know about lean body mass calculator.

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Want to learn more?

Read our complete Lean Body Mass Calculator tutorial with tips, use cases, and FAQs.