Lean Body Mass Calculator
By Santaji GadepatilinUpdated October 27, 2026
Lean body mass is everything in your body except fat — muscles, bones, organs and water. It is used for nutrition and drug dosing.
How to use the lean body mass calculator
Choose your sex and enter height and weight. Lean body mass and the implied body fat percentage appear instantly.
The Boer formula (1984)
Men: LBM = 0.407 × W + 0.267 × H − 19.2
Women: LBM = 0.252 × W + 0.473 × H − 48.3
W = weight in kg, H = height in cm.
Worked example
A man 180 cm and 80 kg:
LBM = 0.407 × 80 + 0.267 × 180 − 19.2 = 61.4 kg → about 23% body fat
A woman 165 cm and 60 kg: LBM = 44.9 kg.
Lean body mass table (Boer formula)
| Height, weight | Men | Women |
|---|---|---|
| 160 cm, 55 kg | 45.9 kg | 41.2 kg |
| 165 cm, 65 kg | 51.3 kg | 46.1 kg |
| 170 cm, 70 kg | 54.7 kg | 49.8 kg |
| 175 cm, 80 kg | 60.1 kg | 54.6 kg |
| 180 cm, 90 kg | 65.5 kg | 59.5 kg |
| 185 cm, 100 kg | 70.9 kg | 64.4 kg |
Other LBM formulas
| Formula | Men | Women |
|---|---|---|
| Boer (1984) | 0.407W + 0.267H − 19.2 | 0.252W + 0.473H − 48.3 |
| James (1976) | 1.1W − 128(W/H)² | 1.07W − 148(W/H)² |
| Hume (1966) | 0.3281W + 0.33929H − 29.5336 | 0.29569W + 0.41813H − 43.2933 |
W is weight in kg and H is height in cm. The James formula becomes unreliable at high body weights.
LBM from body fat percentage
If you know your body fat percentage, from a scan or the body fat calculator:
LBM = Weight × (1 − body fat %)
This is usually more accurate than height-and-weight formulas, especially for very muscular or very lean people.
Protein by lean mass
Some coaches set protein targets per kilogram of lean mass, often 1.6–2.2 g/kg of LBM for people doing regular strength training. See the protein intake calculator.
Using your result
- Protein target: many athletes aim for about 2 g per kg of lean mass.
- Tracking progress: if weight drops but lean mass holds steady, you are losing fat rather than muscle.
For a measurement-based estimate, try the body fat calculator.
Frequently asked questions
What is lean body mass?
Your total weight minus fat — muscles, bones, organs, skin and water.
How accurate is the Boer formula?
It gives a population-average estimate from height and weight only. Very muscular or very overweight people may get less accurate results. Measured methods (DEXA, bioimpedance) are more precise.
Why does lean body mass matter?
It drives your resting calorie burn and is used to set protein targets and some medicine doses.
Is lean body mass the same as muscle mass?
No. Lean body mass includes muscle, bones, organs, skin and water. Muscle is roughly half of it.
Can I increase my lean body mass?
Yes, mainly by building muscle through regular strength training, enough protein and adequate sleep.