💪 Fitness Tool
Lean Body Mass Calculator
Calculate your Lean Body Mass (LBM) — the weight of everything in your body except fat. Essential for protein intake targets and drug dosing.
Lean Body Mass Calculator
Lean Body Mass
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Boer
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kg
James
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kg
Hume
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kg
Fat Mass
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kg
Lean Body Mass Formulas
Lean Body Mass (LBM) represents the total weight of your body minus all fat. It includes muscles, bones, organs, water, and other non-fat tissues. LBM is crucial for calculating protein needs, medication dosing, and metabolic rate.
Boer Formula:
Men: LBM = (0.407 × W) + (0.267 × H) − 19.2
Women: LBM = (0.252 × W) + (0.473 × H) − 48.3
James Formula:
Men: LBM = 1.1W − 128(W/H)²
Women: LBM = 1.07W − 148(W/H)²
Hume Formula:
Men: LBM = (0.3281 × W) + (0.3393 × H) − 29.5336
Women: LBM = (0.2296 × W) + (0.4122 × H) − 43.2933
Where W=weight(kg), H=height(cm)
Men: LBM = (0.407 × W) + (0.267 × H) − 19.2
Women: LBM = (0.252 × W) + (0.473 × H) − 48.3
James Formula:
Men: LBM = 1.1W − 128(W/H)²
Women: LBM = 1.07W − 148(W/H)²
Hume Formula:
Men: LBM = (0.3281 × W) + (0.3393 × H) − 29.5336
Women: LBM = (0.2296 × W) + (0.4122 × H) − 43.2933
Where W=weight(kg), H=height(cm)
Frequently Asked Questions
Why is lean body mass important?
LBM is important for calculating your Basal Metabolic Rate (muscle burns more calories than fat), determining protein needs (typically 1.6–2.2 g per kg of LBM), and medical drug dosing calculations where body fat doesn't affect drug distribution.
How can I increase lean body mass?
Progressive resistance training (weightlifting) combined with adequate protein intake (1.6–2.2 g/kg body weight) and slight calorie surplus is the most effective way to build lean muscle. Consistency over months is key — muscle building is a slow process.
What is the difference between LBM and muscle mass?
Lean Body Mass includes all non-fat tissues: muscle, bones, organs, skin, water, and connective tissue. Skeletal muscle mass is just the muscle portion of LBM, typically 40–50% of total body weight for active adults.