๐ Body Surface Area Calculator
An approximation based on the Mosteller formula.
Enter height and weight to calculate body surface area (BSA) using the Mosteller formula. BSA is widely used in medicine, for example in calculating medication dosages.
How to use
- Enter height (cm).
- Enter weight (kg).
- Body surface area (mยฒ) is calculated automatically.
How the calculation works
Body surface area (BSA) is the total area of the body's surface in square metres. It is widely used in medicine, for example to calculate chemotherapy doses, to assess heart function (cardiac index) and to adjust measures of kidney function. This tool uses the Mosteller formula, published in 1987: BSA (mยฒ) = โ(height (cm) ร weight (kg) รท 3600) The Mosteller formula is used worldwide because it is simple enough to work out on a calculator. Others include the DuBois formula (BSA = 0.007184 ร weight^0.425 ร height^0.725) and, in Japan, the Fujimoto formula; results differ slightly between them.
Worked example
Height 170 cm, weight 70 kg BSA = โ(170 ร 70 รท 3600) = โ3.306 โ 1.82 mยฒ The DuBois formula gives about 1.81 mยฒ for the same person. Average Japanese adults are about 1.7 mยฒ for men and 1.5 mยฒ for women.
Things to be aware of
- In clinical practice, the formula used is set by the hospital or the drug. Do not calculate or change medication doses yourself.
- For people who are very heavy or very thin, calculated values can differ more from actual surface area.
- Children's BSA is sometimes calculated with different formulas.
FAQ
What formula does this use?
The Mosteller formula: BSA(mยฒ) = โ(height(cm) ร weight(kg) / 3600), one of the standard approximations widely used in clinical practice.
Whatโs a typical adult BSA?
Typical adult body surface area is roughly 1.6โ2.0 mยฒ.
What is BSA used for?
Itโs used to calculate chemotherapy drug dosages, IV fluid volumes, and to normalize medical indices like cardiac index. Always follow your physicianโs guidance for actual medical decisions.