What Is Body Surface Area (BSA)?
Body Surface Area (BSA) is the total skin surface area of the human body. Unlike weight, BSA correlates more accurately with metabolic mass and physiological functions. It is used in medicine primarily for calculating chemotherapy doses, cardiac output, fluid replacement in burns, and radiation therapy planning.
BSA Formulas Comparison
| Formula | Year | Equation | Best For |
|---|---|---|---|
| Mosteller ✅ | 1987 | √(H×W÷3600) | General clinical use — simplest |
| DuBois | 1916 | 0.007184×H⁰·⁷²⁵×W⁰·⁴²⁵ | Historical standard |
| Haycock | 1978 | 0.024265×H⁰·³⁹⁶⁴×W⁰·⁵³⁷⁸ | Pediatric dosing |
Average BSA Reference Values
- Newborn: 0.25 m²
- Child (10 years): 1.14 m²
- Average woman: 1.6 m²
- Average man: 1.9 m²
- Obese adult: up to 2.5 m²
Clinical note: BSA is used extensively in oncology to calculate chemotherapy doses. Using actual BSA prevents under-dosing (reduced efficacy) or over-dosing (toxicity) in cancer patients.