Lean Body Mass Calculator

Estimate your lean body mass (LBM) — your total weight minus body fat — using three established formulas: Boer, James, and Hume.

Your Measurements

LBM = total body weight minus fat mass. It includes muscle, bone, water, and organs.

FormulaDescription
BoerMost widely cited formula for clinical use
JamesDerived from a large population study
HumeBased on body density measurements

Results

Avg Lean Mass
55.1 kg
121.5 lb · 78.7% of body
Avg Fat Mass
14.9 kg
32.8 lb · 21% of body
FormulaLBM (kg)LBM (lb)% of body
Boer56123.580%
James56.5124.680.7%
Hume52.8116.475.4%
Average55.1121.578.7%

These formulas use height and weight only. For a more accurate measurement of body composition, consider DEXA scanning or hydrostatic weighing.