Lean Body Mass Calculator
Estimate your lean mass with 3 validated formulas
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Lean Body Mass Calculator
Lean body mass (LBM) is everything in your body except fat — muscle, bone, organs and water. This calculator estimates LBM from your weight, height and sex using three validated equations (Boer, James and Hume) and shows their average plus the resulting fat mass and body-fat percentage. Knowing LBM helps set realistic protein and calorie targets while you lose fat without losing muscle.