Lean Body Mass Calculator
Estimate your lean body mass and fat mass with the Boer formula, in metric or imperial units, from your weight, height and gender.
Your measurements
The Boer formula uses different coefficients for men and women.
How to use this calculator
1. Pick your unit system
Switch between metric (kg / cm) and imperial (lb / ft·in). The form swaps instantly so you never have to convert by hand.
2. Select gender and enter measurements
Choose male or female, then type your current weight and standing height. The Boer formula treats the two genders differently, so this choice matters.
3. Read your lean and fat mass
The headline figure is your estimated lean body mass. Below it you'll see how much of your weight is fat mass and what share of your total weight that represents.
Use it as a starting point
This is an estimate from a population formula, not a body-scan measurement. Methods like DEXA, hydrostatic weighing or skinfold testing give a more personal reading.
About lean body mass
What is lean body mass?
Lean body mass (LBM) is everything in your body that is not stored fat: muscle, bone, organs, water and connective tissue. Total weight minus LBM gives an estimate of your fat mass.
Which formula does this calculator use?
It uses the Boer formula, a widely cited equation that estimates LBM from weight, height and gender. It is an estimate based on population averages, not a direct measurement of body composition.
Not medical advice
This tool is for general information only and is not a substitute for professional advice. For decisions about nutrition, training or medical dosing, consult a qualified healthcare professional.