Lean Body Mass Calculator
Split your weight into lean mass and fat mass.
Your result
Lean body mass is the average of the Boer and James formulas. It includes muscle, bone, organs and water.
Medical disclaimer: This tool is for education and is not medical advice. Read more.
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Frequently asked questions
What does the Lean Body Mass Calculator do?
Split your weight into lean mass and fat mass. Enter your values and the result and chart update instantly.
How accurate is it?
It uses published, widely used formulas. Results are estimates for education and planning, not a diagnosis. Talk to a qualified clinician about decisions affecting your health.
Is my information stored or shared?
No. All calculations run in your browser and nothing you type is sent to a server or saved.
What can I search to find this tool?
People find it by searching for: how much muscle do i have; fat free mass; lean mass for protein needs.