Lean Body Mass Calculator
Estimate your lean body mass (everything except fat mass) using the Boer formula, based on your weight, height, and sex.
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- Works on all devices
Your result
58.1 kg
Lean body mass
AI explanation
Formula
Men: LBM = 0.407×weight + 0.267×height − 19.2. Women: LBM = 0.252×weight + 0.473×height − 48.3Worked example
Male, 75kg, 175cm
| Field | Value |
|---|---|
| Weight | 75 |
| Height | 175 |
| Sex | male |
| Lean body mass | 58.1 |
Assumptions
- Uses the Boer formula (1984), validated against body-density measurements and one of the more accurate weight/height-based LBM estimates available.
- Fat mass is derived as total weight minus estimated lean body mass, so its accuracy depends on the LBM estimate.
- Informational only — not a clinical body-composition measurement.
Frequently asked questions
What is lean body mass?
Lean body mass is your total bodyweight minus fat mass — it includes muscle, bone, organs, and water content.
Why do men and women have different LBM formulas?
The Boer formula's sex-specific constants reflect average differences in body composition and fat distribution between men and women in the population it was derived from.
How accurate is a weight/height-based LBM formula compared to a body scan?
Formula-based estimates are convenient but less precise than direct methods like DEXA or bioelectrical impedance, which measure body composition rather than estimating it from two measurements.
Related calculators
Sources
- Estimated lean body mass as an index for normalization of body fluid volumes in humans — American Journal of Physiology. Effective 01-10-1984, reviewed 13-09-2026.
This calculator provides a general estimate only and does not constitute personalized medical advice. For a precise body composition measurement, consider a DEXA scan.
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