Body Surface Area Calculator
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Calculate body surface area (BSA) using Du Bois, Mosteller, and Boyd formulas. Used in medical dosing and clinical calculations.
Enter your values below and click Calculate for instant results.
Body surface area (BSA) is a measurement of the total surface area of the human body, expressed in square meters. While BMI uses weight relative to height as a proxy for body size, BSA is a direct measure of the body's external surface and is considered a more accurate representation of metabolic mass for clinical purposes.
The average adult BSA is approximately 1.7 to 1.9 square meters. A typical adult male has a BSA of about 1.9 m² while a typical adult female has approximately 1.6 m². These values are used as reference points in medical protocols and drug dosing charts.
BSA is primarily used in medicine for calculating doses of chemotherapy drugs, which are highly potent and must be precisely calibrated to body size. It is also used for cardiac output measurements, burn area assessment, and some kidney function calculations. The use of BSA for drug dosing is based on the observation that many physiological parameters, including glomerular filtration rate and cardiac output, correlate more closely with BSA than with body weight alone.
This calculator uses three established BSA formulas. The Du Bois and Du Bois formula (1916) is the oldest and most historically used in clinical practice. The Mosteller formula (1987) is simpler and widely used because of its ease of calculation. The Boyd formula is more complex but considered accurate across a wider range of body sizes, including pediatric patients.