Lean Body Mass Calculator

Calculate your lean body mass — everything in your body except fat — using three validated scientific formulas.

💪 Lean Body Mass

Lean Mass (kg)

Boer54.7 kg
James55.3 kg
Hume51.1 kg
Est. Body Fat21.9%

💡 Lean Body Mass Formulas

Lean Body Mass (LBM) = total weight minus fat weight. Three formulas estimate LBM from height, weight, and sex: Boer (1984), James (1976), and Hume (1966). Each was validated against different populations.

LBM includes muscle, bone, organs, water, and other non-fat tissue. It's useful for calculating protein needs, assessing body composition, and as an input for the Katch-McArdle BMR formula.

Male, 70 kg, 170 cm: Boer LBM = 57.5 kg, James = 57.3 kg, Hume = 57.0 kg. Estimated body fat ≈ 18%.

Lean Body Mass Calculator FAQ

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