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Lean Body Mass Calculator

Estimate your lean body mass from height and weight with the Boer, James and Hume formulas.

Result

Enter your values and select Calculate to see the result.

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How the Lean Body Mass Calculator works

Lean body mass is everything in your body except fat: muscle, bone, organs and water. This calculator estimates it from your sex, height and weight with three published formulas, and shows the body fat percentage the main one implies. For an estimate from tape measurements, use the Body Fat Calculator.

Formulas

Boer (1984)

men 0.407W + 0.267H − 19.2; women 0.252W + 0.473H − 48.3

W is weight in kg, H height in cm.

James (1976)

men 1.1W − 128(W ÷ H)2; women 1.07W − 148(W ÷ H)2

Hume (1966)

men 0.32810W + 0.33929H − 29.5336; women 0.29569W + 0.41813H − 43.2933

Examples

A man, 180 cm and 80 kg

Boer 61.4 kg, James 62.7 kg, Hume 57.8 kg. By Boer, about 23% of his weight is fat.

A woman, 165 cm and 60 kg

Boer gives about 44.9 kg of lean mass.

Frequently asked questions

Why do the formulas disagree?

Each was fitted to a different group of people. They assume an average build, so they underestimate lean mass for very muscular people.

What is lean mass used for?

Setting protein targets, tracking training progress and, in medicine, some drug doses.

Is this medical advice?

No. It's an estimate for general information.

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