Lean Body Mass Calculator
Estimate your lean body mass using the Boer formula, which is more accurate than BMI for athletes and people carrying extra muscle.
Scan to open on your phone
Point your phone camera at the code to open this tool.
Estimate your lean body mass using the Boer formula, which is more accurate than BMI for athletes and people carrying extra muscle.
How to use Lean Body Mass Calculator
- Open the toolNo signup and nothing to install; it works as soon as the page loads.
- Set “Units”
- Set “Weight”
- Set “Height”
- Set “Sex”
- Read the resultChange any input and the result is recalculated immediately.
Worked example with the defaults
- LEAN BODY MASS · Fat mass: 14.0 kg
- 56.0 kg
Nothing you enter leaves your device
All of the work happens inside your browser. Whatever you type is never packaged up and sent to a server, and no request this page makes carries it.
That makes it safe for contract amounts, personal details and internal documents you would rather not hand to a third party — close the tab and it is gone.
What this tool does not do
Lean Body Mass Calculator only does what a browser can do on its own — it talks to no backend service. So it keeps no history for you and syncs nothing across devices; if you need a record, copy or download the result.
It is also not a substitute for professional judgement. For legal, medical or tax decisions, treat the output as a starting point rather than a final answer.
Frequently Asked Questions
- Why not just use BMI?
- BMI cannot tell muscle from fat. A powerlifter and a sedentary person of the same height can have identical BMIs but very different LBM.