Calculator.CL Logo
Calculator.CL Free Online Calculator
Menu
Fitness Tool

LBM Calculator

Estimate your Lean Body Mass—the weight of everything in your body except fat. Essential for tracking true muscle gains.

Track Gain
Muscle Progress
Scientific
Boer Formula

Understanding Lean Body Mass

Lean Body Mass (LBM) is the calculated weight of your body minus the fat. It includes your skin, bones, ligaments, tendons, organs, and water content. Tracking this is crucial because weight loss can sometimes mean muscle loss, not just fat loss.

The Formulas Used

We primarily use the Boer Formula (1984), which is widely accepted for individuals with a normal BMI range.

Boer (Men): 0.407 × weight + 0.267 × height - 19.2
Boer (Women): 0.252 × weight + 0.473 × height - 48.3

Frequently Asked Questions

Is this accurate for bodybuilders?

Formulas based on height and weight may underestimate LBM for bodybuilders with high muscle mass. A DEXA scan is most accurate.

What is a good LBM?

There isn't a single "good" number, but generally, a higher LBM relative to total weight indicates better fitness and metabolic health.