Lean Body Mass Calculator

Estimate how much of your body is lean mass (muscle, bone, organs, water) versus fat, using the Boer formula.

Enter your weight and height to estimate lean mass.

This is an estimate from a population formula and does not replace clinical body composition testing. It is not medical advice. For an accurate assessment, consult a licensed physician.

Good to know

What is lean body mass?

Everything in your body that is not fat: muscle, bone, organs, and water.

Why does it matter for weight loss?

The goal is to lose fat while keeping lean mass. Crash diets can cost muscle; enough protein and some training help protect it.

How is it calculated?

We use the Boer formula from your height, weight, and sex. It is an estimate, not a body scan.