If you're serious about fitness, weight management, or health tracking, knowing your Lean Body Mass (LBM) is essential. A Lean Body Mass Calculator helps you estimate how much of your body weight is made up of muscles, bones, water, and organs—everything except fat.
At Calculators.at, our free LBM Calculator gives you accurate estimates of your lean mass using simple inputs like height, weight, age, and gender.
Lean Body Mass is your total body weight minus fat mass. It's the healthy, functional part of your body, including:
Example:
If you weigh 80 kg and your body fat is 20%, your Lean Body Mass is:
80 × (1 – 0.20) = 64 kg
Our calculator uses scientifically validated formulas such as:
You simply enter:
It instantly returns your Lean Body Mass in kg or lbs, and sometimes your body fat percentage, if available.
Metric Description LBM Everything in your body except fat Body Fat Mass Total fat in kg or % Total Body Weight = LBM + Fat Mass Knowing both your Lean Body Mass and body fat percentage provides a full picture of your physical health.