Lean Body Mass
Calculate lean body mass using multiple formulas
These calculators provide general information only and are not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider.
How to use Lean Body Mass
- 1Enter your weight, body fat percentage (or use a method like skinfold), and your sex.
- 2Choose the estimation equation if several are offered.
- 3Read your lean mass, the part of your body that is not fat.
Lean body mass explained
Lean mass = Total weight x (1 - body fat fraction)Lean body mass includes muscle, bone, water, and organs; only the fat portion is excluded, so it is higher than just muscle mass.
It is useful for setting protein targets, dosing some medications, and tracking body-composition changes over time.
Frequently asked questions
How is body fat measured?
Methods range from skinfold calipers and bioimpedance scales to DEXA scans, each with different accuracy.
Why does lean mass matter?
It reflects metabolically active tissue and helps tailor nutrition and training, especially as you age.
Is higher lean mass always better?
More is generally favorable for metabolism and strength, but context and overall health matter more than the number alone.