How lean body mass is calculated
Lean body mass (LBM) is your total weight minus fat mass — muscle, bone, organs and water. We use the Boer formula, which estimates LBM from your height, weight and sex. If you enter your body fat percentage, we calculate LBM directly as weight × (1 − body fat%), which is more accurate.
How to use it
Enter your gender, weight and height. Optionally add your body fat percentage (from the body fat calculator) for a more accurate result. Your lean and fat mass appear instantly.
Frequently asked questions
- Why does lean body mass matter?
- LBM drives your metabolism and strength. Preserving it during weight loss is a key goal — eat enough protein and train.
- Which method is more accurate?
- If you know your body fat percentage, that method is most accurate. The Boer formula is a solid estimate from height and weight alone.
- What is a normal lean mass?
- It varies widely with height, sex and training. Track changes over time rather than chasing a single number.
- How do I increase lean mass?
- Resistance training plus adequate protein (1.6–2.2 g/kg) and calories supports muscle growth.