Body Surface Area (BSA) Calculator
Calculate your body surface area using various medical formulas
Body Surface Area (BSA) is a measurement of the total surface area of the human body. It is calculated using height and weight measurements and is widely used in medicine for various purposes, including:
- Drug dosage calculations
- Chemotherapy dosing
- Burn assessment
- Metabolic rate calculations
- Cardiac output measurements
BSA is typically expressed in square meters (m²) and is an important metric for medical professionals in determining appropriate treatment protocols.
Several formulas have been developed to calculate BSA, each with its own advantages and specific applications:
- DuBois Formula (1916): The most widely used formula. BSA = 0.007184 × Height(cm)^0.725 × Weight(kg)^0.425
- Mosteller Formula (1987): A simplified formula that's easier to calculate. BSA = √(Height(cm) × Weight(kg)) ÷ 60
- Haycock Formula (1978): More accurate for children and adults. BSA = 0.024265 × Height(cm)^0.3964 × Weight(kg)^0.5378
- Fujimoto Formula (1968): Developed based on Japanese population data. BSA = 0.008883 × Height(cm)^0.663 × Weight(kg)^0.444
- Schlich Formula (2001): A more recent formula developed using 3D body scanning. BSA = 0.000579479 × Height(cm)^1.24 × Weight(kg)^0.38
BSA is crucial in various medical applications:
- Drug Dosing: Many medications, especially chemotherapy drugs, are dosed based on BSA to optimize efficacy and minimize side effects.
- Burn Assessment: BSA helps determine the extent of burns and guides treatment protocols.
- Cardiac Function: Cardiac index and other cardiovascular measurements are often indexed to BSA.
- Pediatric Applications: BSA is particularly useful in pediatric medicine for dosing and assessment.
- Clinical Trials: BSA is often used to standardize drug doses in clinical research.
While BSA calculations are widely used, it's important to understand their limitations:
- Different formulas may give slightly different results for the same individual.
- BSA formulas may be less accurate for people with extreme body types (very tall, short, or obese).
- Some formulas were developed using specific population data and may be more accurate for certain ethnic groups.
- 3D scanning techniques have shown that traditional formulas may underestimate or overestimate actual BSA.
Which BSA formula should I use?
The DuBois formula is most widely used in clinical practice. However, the Mosteller formula is simpler to calculate and gives similar results. For children, the Haycock formula may be more accurate.
How often should BSA be recalculated?
BSA should be recalculated whenever there are significant changes in weight or height. For medical treatments based on BSA, regular recalculation is important to ensure proper dosing.
Is BSA affected by body composition?
BSA formulas don't directly account for body composition (fat vs. muscle). They only use height and weight measurements, which may affect accuracy for people with unusual body compositions.