Lean Body Mass Calculator
Enter your sex, height, and weight to estimate your lean body mass — everything in your body that isn't fat — using the Boer formula.
Your calculation is performed in your browser.This result is an estimate for informational and educational purposes. It isn’t a diagnosis and isn’t a substitute for advice from a doctor, registered dietitian, or other qualified professional. See our methodology and sources for the formula used and its limitations.
How it works
The Boer formula estimates lean body mass from height, weight, and sex alone, without requiring circumference measurements, making it a quick estimate when you don't have a measuring tape on hand.
Formula & methodology
The Boer (1984) formula estimates lean body mass from weight and height. Fat mass is then whatever remains. The lean mass figure is kept between 1 kg and your total weight.
LBM = (0.407 × weight) + (0.267 × height) − 19.2LBM = (0.252 × weight) + (0.473 × height) − 48.3Fat mass = Weight − LBMLean % = LBM ÷ Weight × 100What each term means
- Weight
- Body weight in kilograms.
- Height
- Height in centimetres.
- LBM
- Lean body mass: everything except body fat.
Worked example
A man who is 180 cm tall and weighs 80 kg has an estimated lean body mass of about 61.4 kg.
Common uses
- —Estimating lean mass without a tape measure, unlike circumference-based body fat methods.
- —Setting protein intake targets based on lean mass rather than total body weight.
- —Tracking how lean mass changes over a training or diet cycle.
Important notes
- —For an estimate based on circumference measurements instead, see the Body Fat Calculator, which uses the U.S. Navy method.
- —Lean body mass includes muscle, bone, organs, and water — not just muscle tissue.