How do you calculate Body Surface Area for dosing in adults?

• A. Mosteller formula: BSA (m^2) = sqrt(height in cm × weight in kg / 3600)
• B. Du Bois formula: BSA = 0.007184 × (height in cm)^0.725 × (weight in kg)^0.425
• C. BSA is approximated by height in inches and weight in pounds divided by 3131
• D. BSA equals weight in kg divided by height in meters

Answer: (B)

Body surface area is used to scale chemotherapy doses to body size so exposure is more consistent across adults. The Du Bois formula, which is considered a standard reference, calculates BSA from height and weight with specific exponents to reflect how surface area grows with those measurements: BSA = 0.007184 × (height in cm)^0.725 × (weight in kg)^0.425. You simply plug in height in centimeters and weight in kilograms, raise each to its respective exponent, multiply the results together, then multiply by 0.007184 to get the BSA in square meters. For example, someone about 170 cm tall and 70 kg would have a BSA around 1.8 m^2.

While the Mosteller formula is also widely used and easier to compute by hand—BSA ≈ sqrt(height cm × weight kg / 3600)—the Du Bois form is the correct one in this context. An estimate using height in inches and weight in pounds divided by 3131 is a rough approximation, not a standard precise method, and a formula like weight in kg divided by height in meters does not produce a valid surface area.