How to Calculate Body Surface Area
What is Body Surface Area?
Body Surface Area (BSA) is the measured or calculated surface area of a human body. It is used in clinical medicine to calculate drug doses (particularly chemotherapy), burn area assessment, and metabolic rate estimation. BSA is considered more accurate than body weight alone for drug dosing.
Step-by-Step Guide
- 1Mosteller formula: BSA = √(H × W / 3600) — simple and widely used
- 2DuBois formula: BSA = 0.007184 × H^0.725 × W^0.425 — original 1916 formula
- 3Haycock formula: BSA = 0.024265 × H^0.3964 × W^0.5378 — most accurate for children
- 4H = height in cm, W = weight in kg, result in m²
Worked Examples
Input
Adult male: 80 kg, 180 cm
Result
BSA ≈ 2.0 m²
Average adult male BSA is 1.9 m²
Input
Child: 20 kg, 110 cm
Result
BSA ≈ 0.76 m²
BSA scales non-linearly with size
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