Lean Body Mass Calculator
Calculate your lean body mass (LBM) and fat mass from your height, weight and gender using the Boer formula.
Lean body mass is calculated with the Boer (1984) equation, which estimates fat-free mass from height, weight and sex. It is a population-level estimate: a DEXA scan or similar measurement is the only way to know your individual lean mass. The figure assumes typical hydration, so it can drift after illness or heavy exercise.
Frequently asked questions
What is lean body mass?
Lean body mass is everything in your body that is not fat — muscle, bone, organs, skin and water. It is the more metabolically active part of your weight, which is why it matters for strength and for calorie needs.
What is a good lean body mass?
It depends heavily on your height, sex and training history, so there is no universal target. The Boer formula used here gives an estimate; tracking the trend alongside resistance training is more useful than any single number.
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