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Calculate your fat-free mass using proven scientific formulas
If known, provides most accurate LBM calculation
Enter your details to calculate lean body mass
Most widely used and validated formula.
Men: 0.407W + 0.267H - 19.2
Women: 0.252W + 0.473H - 48.3
W = weight (kg), H = height (cm)
Most accurate when BF% is known.
LBM = Weight × (1 - BF%/100)
Requires accurate body fat measurement
Alternative method using weight-height ratio.
Men: 1.1W - 128(W/H)²
Women: 1.07W - 148(W/H)²
Used in pharmaceutical calculations.
Men: 0.328W + 0.339H - 29.5
Women: 0.296W + 0.418H - 43.3
Monitor muscle gain/loss during training programs
Calculate accurate protein and calorie needs
Determine appropriate medication dosages
Better metric than weight alone for health
LBM determines baseline calorie expenditure
Track functional mass vs. excess weight
Lean body mass (LBM) is your total body weight minus fat mass. It includes muscles, bones, organs, water, and connective tissue. LBM represents the metabolically active tissue in your body.
LBM includes all non-fat tissue, not just muscle. It consists of skeletal muscle, organs, bones, water, and connective tissue. Muscle mass is only one component of lean body mass.
If you know your body fat percentage, the BF% method is most accurate. Otherwise, the Boer formula is widely validated and commonly used. Results vary between formulas, but all provide reasonable estimates.
LBM is crucial for fitness tracking, nutrition planning, and understanding body composition. It helps determine protein needs, metabolic rate, and whether weight changes are from fat or muscle.
Increase LBM through resistance training, adequate protein intake (1.6-2.2g per kg of bodyweight), progressive overload, and sufficient recovery. Gaining muscle while minimizing fat gain is the goal.
Generally, higher LBM relative to total weight is healthier. However, extreme muscle mass may not be optimal for all sports or individuals. Balance is important based on your goals and health status.
Measure every 4-8 weeks when tracking body composition changes. More frequent measurements may not show significant changes and can be discouraging. Focus on trends over time.
Yes, sarcopenia (age-related muscle loss) typically begins around age 30, with 3-8% loss per decade. Regular resistance training and adequate protein can significantly slow this decline.
Medical Disclaimer: This calculator provides estimates for educational purposes only. LBM calculations are approximations and may not reflect actual body composition. For accurate body composition analysis, consider DEXA scans or professional assessments. Consult healthcare professionals for personalized health and fitness advice.