Lean mass includes muscle, bone, organs and water. It is used in drug dosing and to set protein targets.
How to use the Lean Body Mass Calculator
- Sex
- Weight
- Height
Results update as you type, and every field accepts the units shown in its menu.
How it works
The Boer equation predicts lean mass from weight and height; the rest of your weight is treated as fat.
Inputs explained
| Field | What to enter |
|---|---|
| Sex | Choose one: Male, Female |
| Weight | Units: kg, lb, g, oz, st |
| Height | Units: cm, m, mm, in, ft |
What each result means
- Estimated fat mass = [Weight] – [Lean body mass]
- Estimated body fat = [Estimated fat mass] ÷ [Weight] × 100
Example values
How the main result changes when Weight changes and everything else stays at the example values above:
| Weight (kg) | Lean body mass (kg) |
|---|---|
| 40 | 45.1 |
| 60 | 53.3 |
| 80 | 61.4 |
| 100 | 69.6 |
| 120 | 77.7 |
| 160 | 94 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
Men: LBM = 0.407W + 0.267H − 19.2Women: LBM = 0.252W + 0.473H − 48.3 (W kg, H cm)Worked example
Inputs — Sex: Male; Weight: 80 kg; Height: 180 cm.
Results — Lean body mass = 61.4 kg; Estimated fat mass = 18.6 kg; Estimated body fat = 23.2 %.
Key terms
- Lean body mass
- Body weight minus fat mass.
Frequently asked questions
How accurate is this?
Formula estimates can be several kilograms off; DEXA scans are more precise.
Is lean mass the same as muscle mass?
No, it also includes bone, organs and water.
What formula does the Lean Body Mass Calculator use?
Men: LBM = 0.407W + 0.267H − 19.2.