💪 Lean Body Mass Calculator
Estimate your lean body mass (muscle, bone, and organs, excluding fat) using the Boer formula.
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Your Result
Lean body mass estimates from formulas are approximations. Methods like DEXA scans or bioelectrical impedance provide more precise body composition results.
How the Lean Body Mass Calculator Works
Lean body mass (LBM) is your total body weight minus fat mass — it includes muscle, bone, organs, and water. This calculator uses the Boer formula, one of the most widely cited equations for estimating LBM from height and weight alone.
Formula (Boer)
Women: LBM = 0.252 × weight (kg) + 0.473 × height (cm) − 48.3
Why Lean Body Mass Matters
LBM is often used to estimate calorie and protein needs, dose certain medications, and track changes in body composition during training or weight loss that the scale alone won't show.
Frequently Asked Questions
How is lean body mass different from muscle mass?
Lean body mass includes all non-fat tissue — muscle, bone, organs, and body water — not just skeletal muscle. Muscle mass is a subset of lean body mass.
How accurate is the Boer formula?
It's a well-validated estimate for the general population but can be less precise for people with very high muscle mass or very high body fat. Direct measurement methods like DEXA are more accurate.
What is a healthy lean mass percentage?
It varies by sex, age, and fitness level. Generally, higher lean mass percentage relative to total weight indicates lower relative body fat, though optimal ranges differ between men and women.