Lean Body Mass Calculator
Estimate your lean body mass (everything except fat) using the Boer, James and Hume formulas.
About the Lean Body Mass Calculator
Lean body mass (LBM) is your total weight minus body fat: muscles, bones, organs and water. It is used to set protein targets, calculate some medicine doses and track whether you are losing fat or muscle on a diet.
How to Use the Lean Body Mass Calculator
- Select your units and gender.
- Enter your height and weight.
- Press Calculate to compare three LBM formulas.
Formula and How It Works
Boer formula: men LBM = 0.407 × weight (kg) + 0.267 × height (cm) − 19.2; women LBM = 0.252 × weight + 0.473 × height − 48.3. The James and Hume formulas are shown for comparison.
Frequently Asked Questions
Is lean body mass the same as muscle mass?
No. Lean mass includes muscle plus bones, organs, skin and water. Muscle is usually 40–50% of lean mass.
How can I increase lean body mass?
Strength training 2–4 times a week, enough protein and good sleep are the most effective ways.
Results are estimates for general information and are not medical or veterinary advice. Please speak to a qualified professional about your own situation.