Lean Body Mass Calculator
Estimate lean mass and fat mass.
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Estimate your lean body mass
Lean body mass is everything in your body except stored fat, including muscle, bone, organs and water. Enter your weight, height and gender using either unit system to estimate your lean mass and the remaining fat mass using the Boer formula. Athletes and anyone tracking muscle often watch lean mass rather than total weight on the scale. The result is an estimate, not a clinical reading.
Why track it
During weight change, lean mass shows whether you are keeping muscle, something total body weight alone cannot reveal.
Frequently asked questions
What counts as lean body mass?
Everything that is not stored body fat, including muscle, bone, organs, connective tissue and body water.
What formula is used?
It uses the Boer formula, a common estimate of lean body mass based on weight, height and gender.