Lean Body Mass Calculator
Estimate lean body mass (LBM) using the Boer formula from height, weight, and gender. See fat mass and body fat percentage against a healthy range reference.
Gender
cm
kg
years
Results
Lean Body Mass (Boer)
54.7 kg
Fat Mass
15.3 kg
Body Fat %
21.9%
Healthy Range Reference
~75–88% of body weight (healthy)
How is Lean Body Mass Calculated?
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 from height and weight:
Female: LBM = 0.252 × Weight(kg) + 0.473 × Height(cm) − 48.3
Example
A 170 cm, 70 kg male: LBM = 0.407 × 70 + 0.267 × 170 − 19.2 ≈ 54.2 kg. If he enters 18% body fat, fat mass = 0.18 × 70 = 12.6 kg, leaving about 57.4 kg of lean tissue — close to the formula-based estimate.
Common Use Cases
- Estimating body composition and tracking muscle gain or fat loss over time.
- Setting a weight target that preserves lean tissue during a cut.
- Estimating the metabolically active tissue mass for nutrition planning.
- Providing a rough baseline before a DEXA scan or bioimpedance test.
FAQs
What is a healthy lean body mass?
Healthy lean mass varies with gender, age, and training level. In general, lean body mass is roughly 75–88% of body weight for men and 68–82% for women. Body fat percentages around 10–20% for men and 18–28% for women are commonly considered healthy.
Is the Boer formula accurate?
The Boer formula is a widely used estimation method that works well for average adults, but it is an estimate. Athletes and very muscular or very obese individuals may be underrepresented — the formula does not directly measure body fat. For high precision use DEXA, hydrostatic weighing, or skinfold calipers with a trained professional.
What's the difference between lean body mass and muscle mass?
Lean body mass includes everything that isn't fat — muscle, bone, internal organs, and water. Muscle mass is only a part of that. The two terms are often used loosely interchangeably, but they are not identical.