Calculator
Example Data Table
| Sex | Weight (kg) | Height (cm) | Equation | Lean Body Weight (kg) | Fat Mass (kg) |
|---|---|---|---|---|---|
| Male | 80 | 180 | Janmahasatian | ≈ 61.6 | ≈ 18.4 |
| Female | 65 | 165 | Boer | ≈ 43.9 | ≈ 21.1 |
| Male | 95 | 175 | Hume | ≈ 66.2 | ≈ 28.8 |
Formulas Used
Variables: Weight W in kilograms, Height H in centimeters, BMI in kg/m².
How to Use This Calculator
- Select your unit system and sex.
- Choose an equation required by your guideline.
- Enter weight and height, then press Calculate.
- Review lean body weight, BMI, and derived composition.
- Use the export buttons to save results as CSV or PDF.
FAQs
1) What is lean body weight?
Lean body weight estimates everything except fat mass, including organs, muscle, and water. It can support dosing or assessment when total weight may overestimate drug distribution.
2) Which equation should I choose?
Follow your clinical or institutional protocol. Janmahasatian is popular for BMI-based adjustment. Boer and Hume are height-weight models. James is older and sometimes avoided in severe obesity.
3) Does this replace professional medical advice?
No. Results are estimates for education and screening. Clinical decisions should consider the patient, medication, comorbidities, and local guidance.
4) Why does the result change by equation?
Each equation was developed from different populations and assumptions. Some scale more strongly with height, others with BMI. That is why protocols often specify one equation.
5) What if my inputs look unusual?
The calculator will warn when height or weight is outside typical adult ranges. Double-check unit selection and measurement accuracy before using the result.
6) Can I use imperial units?
Yes. Enter pounds and feet/inches. The calculator converts values internally to metric for equations, then displays outputs in your chosen unit system.
7) What’s included in the CSV and PDF exports?
Exports include sex, equation, metric-converted inputs, BMI, lean body weight, fat mass, and body fat percentage. This supports quick documentation and sharing.