💪 Lean Body Mass Calculator (LBM)
Estimate body weight without fat
📌 What is Lean Body Mass?
Lean body mass (LBM) is body weight minus fat weight. It includes muscles, bones, organs, and fluids. Useful for drug dosing, health assessment, and nutrition.
Estimate Your Lean Body Mass (LBM)
Lean body mass is the weight of everything in your body except stored fat: muscle, bone, organs, and the water they contain. This calculator estimates that figure from your height, weight, and sex using established formulas such as Boer, Hume, and James. Comparing the results from different equations gives a useful range rather than relying on a single number, since each formula was developed from a different study population.
Knowing your lean mass is valuable because total body weight alone hides what is changing underneath. Two people at the same weight can have very different amounts of muscle and fat, and tracking lean mass helps reveal whether a weight change comes from muscle, fat, or fluid.
Who Finds It Useful
Athletes and people training for strength use lean body mass to monitor whether their programme is building muscle. It is also used in nutrition planning, since protein needs and calorie targets are often tied to lean mass rather than total weight.
To use the tool, enter your height, weight, and sex, and it returns LBM estimates from each formula. The values are mathematical estimates, not direct measurements like a body-composition scan, so treat them as a helpful guide. For medical or detailed body-composition decisions, consult a qualified professional. The calculator is free and works on mobile and desktop.