Lean Body Mass (Boer Formula) Formula

Understand the math behind the lean body mass (boer formula). Each variable explained with a worked example.

Use the Lean Body Mass (Boer Formula)

Formulas Used

Lean Body Mass

lbm_kg = 0.407 * weight_kg + 0.267 * height_cm - 19.2

Lean Body Mass

lbm_lbs = (0.407 * weight_kg + 0.267 * height_cm - 19.2) * 2.20462

Estimated Body Fat

est_body_fat_pct = (1 - (0.407 * weight_kg + 0.267 * height_cm - 19.2) / weight_kg) * 100

Variables

VariableDescriptionDefault
weight_lbsBody Weight(lbs)180
height_inchesHeight(inches)70
weight_kgDerived value= weight_lbs * 0.453592calculated
height_cmDerived value= height_inches * 2.54calculated

How It Works

Boer Formula for Lean Body Mass (Male)

LBM (kg) = 0.407 x Weight(kg) + 0.267 x Height(cm) - 19.2

The Boer formula estimates lean body mass directly from height and weight without requiring a body fat measurement. It is considered one of the more accurate predictive LBM equations.

Worked Example

A 180 lb, 70-inch tall male.

weight_lbs = 180height_inches = 70
  1. 01Weight = 81.6 kg, Height = 177.8 cm
  2. 02LBM = 0.407 x 81.6 + 0.267 x 177.8 - 19.2
  3. 03= 33.2 + 47.5 - 19.2 = 61.5 kg (135.6 lbs)
  4. 04Est body fat = (1 - 61.5 / 81.6) x 100 = 24.6%

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