Massa Corporal Magra — Calculadora Online Grátis
Lean muscle mass using Boer, James and Hume formulas with fat vs lean body composition chart
Lean Body Mass (LBM) is everything in your body that isn't fat — muscle, bone, organs, blood, and water. Knowing your LBM is more actionable than total body weight for fitness goals, since it tells you how much metabolically active tissue you have, informs protein targets, and helps track whether your training is building muscle or just changing scale weight.
Frequently Asked Questions
Sobre Esta Calculadora
Lean body mass is one of the most useful metrics for anyone focused on body composition rather than just weight. Because muscle is denser and metabolically more active than fat, two people with the same body weight can have very different LBMs — and very different resting metabolic rates, strength levels, and health risks.
The three formula-based methods (Boer, James, Hume) estimate LBM from height and weight without requiring body fat measurement. They differ in their population validation samples, so results can vary by 3–8 kg between formulas. If you have a reliable body fat percentage from the Navy method or body fat calipers, the direct calculation (Weight × (1 − BF%)) is more accurate than any formula.
Tracking LBM over time — rather than scale weight — is particularly valuable during body recomposition phases where you're building muscle and losing fat simultaneously. Scale weight might stay the same while LBM increases, which represents genuine progress.
A massa magra é tudo em seu corpo que não é gordura.
Fórmula
LBM = Weight × (1 - Body Fat%)
Exemplo Resolvido
LBM calculation for a 80 kg man at 20% body fat using multiple formulas
Entradas:
- Body weight: 80 kg
- Height: 175 cm
- Sex: Male
- Body fat (Navy method): 20%
Passo a Passo:
- Direct method (if body fat % known): LBM = 80 × (1 − 0.20) = 64.0 kg
- Boer formula (male): LBM = 0.407 × 80 + 0.267 × 175 − 19.2 = 32.56 + 46.72 − 19.2 = 60.1 kg
- James formula (male): LBM = 1.1 × 80 − 128 × (80/175)² = 88 − 128 × 0.209 = 88 − 26.7 = 61.3 kg
- Hume formula (male): LBM = 0.3281 × 80 + 0.33929 × 175 − 29.5336 = 26.2 + 59.4 − 29.5 = 56.1 kg