Lean Body Mass Calculator
Estimate your lean body mass (everything except fat) with the Boer, James and Hume formulas.
About the Lean Body Mass Calculator
Lean body mass includes muscle, bone, organs and water. It's used for some drug doses and for the Katch-McArdle calorie equation. These formulas use height and weight only; a body fat measurement gives a more personal figure: lean mass = weight × (1 − body fat %).
The formula
Boer: men 0.407W + 0.267H − 19.2; women 0.252W + 0.473H − 48.3
- W
- weight in kg
- H
- height in cm
- James
- men 1.1W − 128(W/H)²; women 1.07W − 148(W/H)²
Worked example
Example: Lean body mass (Boer) = 154 lb
- Inputs: Units: lb / ft; Sex: Male; Height: 6 ft; and: 10 in; Weight: 180 lb.
- Formula: Boer: men 0.407W + 0.267H − 19.2; women 0.252W + 0.473H − 48.3
- Result: Lean body mass (Boer) = 154 lb
Things to keep in mind
- This is an estimate for general information, not medical advice. Talk to a doctor or other qualified professional about your health.
Questions people ask
Why do the formulas disagree?
They were derived from different groups of people; the Boer formula is often preferred for adults of normal build.
Does lean mass equal muscle?
No, muscle is roughly half of lean mass; the rest is bone, organs and water.