Lean Body Mass Calculator (Boer Formula)
Enter your sex, weight and height to estimate how much of your body weight is lean mass.
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Formula
- Men:
LBM = 0.407 x weight (kg) + 0.267 x height (cm) - 19.2 - Women:
LBM = 0.252 x weight (kg) + 0.473 x height (cm) - 48.3 Fat mass = weight - LBM
Worked example
Man, 70 kg and 175 cm: 0.407 x 70 = 28.49, 0.267 x 175 = 46.725, so LBM = 28.49 + 46.725 - 19.2 = 56.0 kg. Fat mass is 14.0 kg and lean share is 80.0%.
Frequently asked questions
What is lean body mass?
Lean body mass is everything that is not fat: muscle, bone, organs and water. A man of 70 kg and 175 cm has about 56.0 kg of it, which is 80% of his weight.
What is the Boer formula?
For men it is 0.407 x weight (kg) + 0.267 x height (cm) - 19.2. For women it is 0.252 x weight + 0.473 x height - 48.3. A woman of 60 kg and 165 cm gets 44.9 kg.
Is this the same as body fat percentage?
It is related but not the same. Body fat mass here is weight minus estimated lean mass, so the 70 kg example has 14.0 kg of fat. Formulas estimate from height and weight only and cannot measure fat directly.
How accurate is the estimate?
It is an estimate for typical adults. Scans such as DEXA are more accurate, and very muscular or very lean people can differ by several kilograms from the formula.