Body Surface Area (BSA) is a critical metric used across various medical disciplines. It estimates the total external surface area of the human body, offering a more physiologically relevant measure than weight or Body Mass Index (BMI) for specific clinical decisions.
Certain medical treatments—especially chemotherapy and critical care interventions—require high dosing precision. Weight-based dosing can be misleading, particularly in patients at weight extremes. BSA provides a better approximation of metabolic mass and drug distribution, making it a preferred standard in:
Drug Dosing: Many drugs, particularly cytotoxic agents, are dosed per square meter (mg/m²). Using BSA helps avoid under- or overdosing in patients with unusual body compositions.
Renal and Cardiac Function: GFR and cardiac output are often normalized to BSA to compare patients fairly, regardless of size.
Burn Management: BSA calculations are also used to estimate the percentage of skin area affected in burn cases, guiding fluid replacement therapy.
Several formulas have been developed to calculate BSA based on height and weight. The most commonly used are:
Each has clinical backing depending on population and context. You can use our free BSA calculator to compare results across methods.
As precision medicine evolves, BSA remains a foundational tool. Adjusting medical parameters to surface area ensures treatment efficacy and reduces toxicity, aligning with modern personalized care principles.
Accuracy in BSA matters. Manual calculation increases the risk of error. Our BSA calculator provides reliable, real-time results using all major medical formulas—no signup or software needed.