Body Surface Area Calculator
What is Body Surface Area (BSA)?
Body Surface Area (BSA) is the total surface area of the human body. It's a crucial measurement in medicine — used to calculate chemotherapy dosages, assess burn severity, estimate renal clearance, and adjust medication levels. Because BSA generally correlates with metabolic mass, it often provides a better dosing reference than body weight alone.
Common BSA Formulas
| Formula | Equation (Height cm, Weight kg) | Notes |
|---|---|---|
| Mosteller | √(Height × Weight / 3600) | Simplest; very popular in clinics |
| Du Bois & Du Bois | 0.007184 × Height0.725 × Weight0.425 | Classic standard, frequently cited |
| Haycock | 0.024265 × Height0.3964 × Weight0.5378 | Developed from pediatric data |
| Gehan & George | 0.0235 × Height0.42246 × Weight0.51456 | Based on direct measurements |
| Boyd | 0.0003207 × Weight(g)(0.7285 - 0.0188 log10(g)) × Height0.3 | Uses weight in grams; accurate over wide range |
How to Use This Calculator
- Enter your height (centimeters or inches) and weight (kilograms or pounds).
- Choose a formula from the dropdown — Mosteller is a good everyday choice.
- Click Calculate to see your BSA in square meters (m²).
- The result updates instantly when you switch formulas and recalculate.
Why BSA Matters
Drug dosing for chemotherapeutics, cardiac medications, and pediatric prescriptions often relies on BSA rather than weight alone. It also guides fluid maintenance, burn size estimation (rule of nines), and glomerular filtration rate adjustments. Always consult a healthcare professional for medical decisions.
Disclaimer: This tool is for educational purposes only and does not replace professional medical advice.
