Where BSA is used
Chemotherapy dosing, cardiac index, and eGFR normalization all rest on body surface area. It scales better than weight alone for physiological processes tied to metabolic rate rather than mass.
- • Cardiac index = cardiac output ÷ BSA; normal is roughly 2.5–4.0 L/min/m².
- • eGFR is reported per 1.73 m², the historical average adult BSA.
- • Formula choice can change a chemotherapy dose by a few percent — follow local protocol.
FAQ
What is a normal body surface area?
About 1.9 m² for an average adult man and 1.6 m² for an average adult woman. The reference value used for eGFR normalization is 1.73 m².
Which BSA formula is most accurate?
Du Bois and Mosteller perform similarly in adults; Haycock is often preferred in pediatrics. Consistency with your institution's protocol matters more than the marginal accuracy difference.
Why is chemotherapy dosed by BSA?
BSA correlates better than weight with metabolic rate and drug clearance, giving a more consistent exposure across body sizes — though the practice is increasingly debated.
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