Lean Body Mass Calculator
Calculate your Lean Body Mass (fat-free mass) using three established formulas — Boer, James and Hume — to get a reliable range.
What Does This Tool Do?
Calculate lean body mass (LBM) — the weight of everything in your body except fat — using three clinical formulas: Boer, James and Hume. Shows fat mass and estimated body fat percentage too.
Key Features
3 Formulas
Boer, James and Hume compared side by side.
Fat Mass
Fat mass shown for each formula.
Body Fat %
Estimated body fat percentage.
Instant
Immediate results.
How to Use
- Enter your weight in kg.
- Enter your height in cm.
- Select your sex.
- Click Calculate LBM.
Frequently Asked Questions
What is Lean Body Mass?▾
LBM is total body weight minus fat mass — it includes muscle, bone, organs, skin, blood and water. Also called fat-free mass (FFM).
Why three formulas?▾
Each formula was developed using different study populations and measurement methods. Comparing all three gives a more reliable estimate than any single formula alone.
How is body fat % estimated?▾
Body Fat % = (Weight − LBM) / Weight × 100. This uses the average LBM from the three formulas.
Complete Guide to Lean Body Mass Calculator
When To Use This Tool
Use Lean Body Mass Calculator whenever you need fast, accurate output without installing software. This tool is designed for speed, clarity, and repeatable results for day-to-day work.
Best Practices for Accurate Results
- Double-check the format of your input before running the tool.
- Test with a small sample first, then process larger data.
- Use Related Tools to verify, convert, or transform the output.
Why Users Prefer AdeDX
AdeDX tools are browser-based, free to use, and built to work across desktop and mobile devices. Most processing happens directly in your browser for fast performance and improved privacy.