Lean Body Mass Calculator
Estimates the part of your weight that is not fat.
Lean mass (Boer)
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Share of your weight — %
Lean mass from your body fat % —
Fat mass from your body fat % —
Reading this —
The formula
men: 0.407w + 0.267h − 19.2 women: 0.252w + 0.473h − 48.3 from body fat: w × (1 − body fat % ÷ 100)
w is weight in kg and h is height in cm.
What to watch out for
The formula is from Boer (1984). It suits adults of ordinary build and can be wrong for very muscular or very overweight people, because it only sees height and weight. A measured body fat percentage, if you trust it, gives a more personal figure.
Frequently Asked Questions
What is the lean mass of a 180 cm, 80 kg man?
About 61.4 kg on the Boer formula.
How do I work it out from body fat?
Take away the fat. At 75 kg and 20% body fat, that leaves 60.0 kg.
Is lean mass the same as muscle?
No. It is everything other than fat, including bone, organs and water. Muscle is a part of it.