Body Surface Area Calculator
Calculate your body surface area (BSA) using different medical formulas based on your height and weight with our free online calculator.
Category: Fitness & Health
Different formulas can give slightly different results. DuBois & DuBois is the most widely used.
Frequently Asked Questions
What is Body Surface Area (BSA) used for?
Body Surface Area (BSA) is used in many medical contexts, including determining medication dosages (particularly chemotherapy), calculating cardiac index (cardiac output relative to body size), estimating metabolic rate, determining fluid replacement needs for burn patients, and normalizing physiological measurements across different body sizes.
Which BSA formula is most accurate?
No single BSA formula is universally most accurate for all populations. The DuBois & DuBois formula is the most widely used historically, but the Mosteller formula is often preferred for its simplicity and reasonable accuracy. The Haycock formula may be more accurate for pediatric patients. For clinical purposes, consistency in using the same formula is often more important than which specific formula is chosen.
How is BSA different from BMI?
Body Surface Area (BSA) measures the total surface area of the human body in square meters, while Body Mass Index (BMI) is a ratio of weight to height squared that categorizes weight status. BSA is primarily used for medical calculations like drug dosing, while BMI is used to assess weight categories relative to height. They serve different clinical purposes and cannot be directly converted between each other.
What is a normal BSA range for adults?
The typical BSA range for adults is approximately 1.6-2.0 m² for women and 1.8-2.3 m² for men, but there is no specific 'normal' range as BSA naturally varies with height and weight. Rather than comparing to population norms, BSA is most useful for individual-specific calculations in medical contexts.