Lean Body Mass Calculator
Estimates lean body mass with the Boer formula from sex, height, and weight, and reports the remaining weight as fat mass.
What this calculator does
The Lean Body Mass Calculator estimates your result instantly from the values you enter, using standard health & fitness formulas. Estimates lean body mass with the Boer formula from sex, height, and weight, and reports the remaining weight as fat mass. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.
Result
About Lean Body Mass Calculator
The Lean Body Mass Calculator uses the Boer formula. For males it computes 0.407 × weight + 0.267 × height − 19.2; for females it uses 0.252 × weight + 0.473 × height − 48.3, with weight in kilograms and height in centimetres.
Fat mass is the remaining weight: your total weight minus the lean body mass.
Formula & Mathematical Calculation
Lean Body Mass (kg) = f(Sex, Height (cm), Weight (kg))
Calculated according to standard health formulas implemented in the calculator core.
Calculation Example
For a male of 175 cm and 75 kg: 0.407 × 75 + 0.267 × 175 − 19.2 = 30.525 + 46.725 − 19.2 = 58.05 kg.
The tool reports a Lean Body Mass of about 58.1 kg and a Fat Mass of about 17 kg (75 − 58.05).
Key Benefits
- Estimates lean mass with the Boer formula
- Also reports fat mass from your total weight
- Uses separate equations for males and females
- Needs only height and weight, with no calipers
How to Use this Calculator
-
Select sex
Choose Male or Female to pick the Boer equation. -
Enter height and weight
Type your height in centimetres and weight in kilograms. -
Calculate
Select Calculate to see lean body mass and fat mass.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
- Results use standard published formulas and account only for the values entered above.
- Rounding is applied for display; the underlying calculation uses your full precision.
- Results are returned in the same units you enter, unless the tool states the output unit.
What it does not cover
- Lean Body Mass Calculator produces a calculated result for reference and learning, not a certified or official measurement.
- Real-world outcomes differ when tolerances, rounding rules or local standards apply.
- Definitions and standards vary by region and change over time; verify the convention that applies to your case.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For work where the result carries real consequences, confirm it against an authoritative source.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.