Lean body mass calculator
Estimate lean body mass with the Boer formula.
What this calculator covers
Use this calculator to estimate lean body mass from body weight, height, and the selected sex-based Boer formula. It is useful when you want a quick body-composition estimate without jumping straight to a lab test.
Lean mass formulas are still just formulas. They can help frame a discussion about body composition, but they should not be confused with direct measurements from imaging or more controlled body-fat testing methods.
Frequently asked questions
- What does lean body mass actually measure?
- Lean body mass is the portion of total weight that is not fat — it includes muscle, bone, organs, and water. The Boer formula estimates this value from weight and height using sex-specific coefficients, so it is an approximation rather than a direct lab measurement.
- Why does the formula differ for males and females?
- The sex-specific coefficients in the Boer equation reflect differences in average body composition between males and females. Because the weight of muscle and bone relative to total body mass tends to differ by sex, using the same coefficients for both would introduce systematic error into the estimate.
- How accurate is this estimate compared with a DEXA scan?
- Formula-based lean mass estimates like Boer are less precise than imaging methods such as DEXA or hydrostatic weighing, which directly measure tissue compartments. The formula is useful for tracking rough trends over time, but a clinical assessment is more appropriate when precision matters.
- Can I use this result to set a protein or calorie target?
- Lean body mass is often used as a reference point for calculating protein needs. However, the number here is an estimate, so any nutrition targets built from it should be treated as starting points and adjusted based on actual results.
Tool
Run the calculation
Result
RESULT · LEAN MASS
â„–139
Primary result
62.2 kg
Using the Boer male formula, 82.0 kg and 180.0 cm estimate lean body mass at 62.2 kg.
- Metric weight used
- 82.00 kg
- Metric height used
- 180.00 cm
- Lean body mass (kg)
- 62.2 kg
- Lean body mass (lb)
- 137.2 lb
Step-by-step solution
- 1.Convert the selected inputs to metric units: 82.00 kg and 180.00 cm.
- 2.Run the Boer male equation: 0.407 x 82.00 + 0.267 x 180.00 - 19.2.
- 3.Round the result to 62.2 kg or 137.2 lb for display.
Walkthrough
Visual walkthrough
Lean body mass estimates try to separate the non-fat component of body weight by blending total weight with height in a sex-specific formula.
01
Convert to metric inputs
82.00 kg and 180.00 cm
The Boer coefficients are published for kilograms and centimeters.
02
Apply the Boer equation
0.407w + 0.267h - 19.2
The sex-specific coefficient set changes how weight and height contribute to the estimate.
03
Read the lean-mass estimate
The result is a modeling shortcut, not a lab measurement of body composition.
62.2 kg