Lean Body Mass Calculator

Calculate lean body mass using the Boer, James, and Hume formulas. Shows LBM, fat mass, and body fat percentage.

Gender

Units

Weight (kg)

Height (cm)

Boer Formula (1984)

58.0

LBM (kg)

17.0

Fat mass (kg)

22.6%

Body fat %

James Formula (1976)

59.0

LBM (kg)

16.0

Fat mass (kg)

21.3%

Body fat %

Hume Formula (1966)

54.4

LBM (kg)

20.6

Fat mass (kg)

27.4%

Body fat %

How lean body mass is calculated

Lean body mass (LBM) is total body weight minus fat mass. The Boer formula (1984) is the most widely used; the James formula (1976) uses a quadratic weight/height term; and the Hume formula (1966) is commonly used in pharmacokinetics. All three take weight (kg) and height (cm) as inputs, with separate equations for males and females.

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