Lean Body Mass (LBM) Calculator

What is Lean Body Mass (LBM) Calculator?

Lean Body Mass (LBM) represents the total weight of your body excluding adipose fat tissue—encompassing skeletal muscle, bone density, organs, blood volume, and intracellular water. Our Lean Body Mass Calculator estimates your lean mass, fat-free mass percentage, and total fat mass across three clinical anthropometric equations (Boer, James, and Hume) directly in your browser.

Designed for accuracy, speed, and privacy, this tool runs entirely on your local device with zero network latency.

How to Use the Lean Body Mass (LBM) Calculator

1. 1
   Select your Biological Sex and Measurement Unit System (Metric cm/kg or Imperial ft/in/lbs).
2. 2
   Input your current Body Weight and Height measurements accurately.
3. 3
   Review your estimated Lean Body Mass (kg and lbs), Lean Mass Percentage, and Fat Mass breakdown.
4. 4
   Compare results across the Boer (1984), James (1976), and Hume (1966) comparative clinical equations.

Formula & Calculation Logic

Calculates fat-free mass from height (cm) and weight (kg). The Boer formula is standard in clinical pharmacology for estimating drug distribution volumes, alongside historical James and Hume equations.