Kalkulator beztłuszczowej masy ciała
The detailed guide below is currently available in English.
What counts as lean body mass
Lean body mass is everything in your body that is not fat: muscle, bone, organs, blood, and water. Formulas like Boer's estimate it from height and weight with a gender term, so it is fast and free but only an approximation. Direct methods — DEXA scans, underwater weighing, air-displacement plethysmography — measure composition instead of predicting it and can differ by several percentage points.
Why athletes track LBM
Lean mass drives resting metabolism, so knowing it helps set realistic calorie and protein targets, and tracking it separates muscle gained from fat lost when weight alone barely moves. Many medication doses are also scaled to lean rather than total mass in research settings. If your estimated body fat percentage looks far off from a lab measurement, trust the lab. This tool provides estimates, not medical advice.
Częste pytania
How is the Boer formula defined?
For men: LBM = 0.407 × weight(kg) + 0.267 × height(cm) − 19.2. For women: LBM = 0.252 × weight(kg) + 0.473 × height(cm) − 48.3. It was published in 1984 from measured body composition data and remains a common quick estimator.
Is lean body mass the same as muscle?
No. Muscle is only part of lean mass, which also includes bones, organs, and body water. You cannot convert an LBM figure directly into a muscle-mass number without imaging or other direct measurement.