Body Surface Area
BSA - Du Bois, Mosteller & Haycock
Calculate body surface area using three validated formulas. Used in medicine for drug dosing.
Body Surface Area (BSA) Calculator
Calculate body surface area using Du Bois, Mosteller, and Haycock formulas.
About Body Surface Area
BSA is a core scaling variable in clinical medicine. Unlike BMI, which is a ratio, BSA is an absolute size measurement — the actual area that would cover your body if you unfolded all your skin. It correlates tightly with metabolic rate, cardiac output, kidney function, and drug clearance.
The Three Formulas
Du Bois (1916): 0.007184 × W^0.425 × H^0.725 Mosteller (1987): √(H × W / 3600) Haycock (1978): 0.024265 × W^0.5378 × H^0.3964 Du Bois is the classical reference. Mosteller is the most commonly used today because it's easier to compute by hand and agrees with Du Bois to within 5%. Haycock performs best at the extremes — very small children or very large adults.
Where BSA Is Used
Chemotherapy dosing: mg per m² rather than per kg. Cardiac index: cardiac output / BSA, comparing heart function across body sizes. Burn assessment: estimating percentage of skin affected (rule of nines). Drug clearance: many drugs have pharmacokinetics that scale with BSA. Pediatric dosing adjustments.
Formula
Medical Disclaimer
This calculator is for educational and reference use only. Never use BSA calculations to modify or calculate medication doses on your own. Clinical dosing requires physician oversight and validated software.