Health & Fitness Tools

Lean Body Mass (LBM) Calculator

Calculate your Lean Body Mass (LBM)—the combined weight of your muscles, bones, organs, and body water—using validated anthropometric equations developed by Boer, James, and Hume.

All physiological calculations run locally in your browser.
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How to Use Lean Body Mass (LBM) Calculator

1

Select Gender

Choose Male or Female.

2

Enter Current Weight & Height

Provide measurements in pounds/inches or kilograms/centimeters.

3

View Body Composition

See your Lean Body Mass, total fat mass, and estimated body fat percentage.

About Lean Body Mass (LBM) Calculator

Lean Body Mass represents your total weight minus adipose body fat. Tracking LBM is essential for strength athletes and dietitians because preserving lean mass during weight loss ensures that weight shed comes exclusively from fat rather than skeletal muscle tissue.

Key Features

  • Calculates LBM using Boer, James, and Hume clinical formulas
  • Outputs Lean Mass, Fat Mass, and estimated Body Fat %
  • Calculates Fat-Free Mass Index (FFMI) for athletic benchmarking
  • Dual unit support: Imperial (lbs) and Metric (kg)
  • Completely private on-device execution

Frequently Asked Questions

Muscle mass refers specifically to skeletal muscle tissue. Lean Body Mass encompasses everything in your body that is not fat—including muscles, bones, internal organs, skin, and blood.
Lean Body Mass Calculator – Boer, James & Hume Formulas | Toolxilla | Toolxilla