Calculate body surface area in square meters using the Mosteller formula. Accepts metric (kg/cm) or imperial (lb/ft/in) input. For educational use only.
Formula (Mosteller): BSA (m2) = sqrt(height_cm x weight_kg / 3600). Source: Mosteller, NEJM 1987.
Result in square meters (m2). Do not use this result directly for medication dosing. All drug doses must be calculated and verified by a licensed healthcare provider.
Body surface area (BSA) is a measure of the total surface area of the human body. It is used in clinical settings to scale drug doses, particularly for chemotherapy, and in formulas for cardiac index and other physiological parameters.
For example, a person who weighs 70 kg and is 170 cm tall: BSA = sqrt(170 x 70 / 3600) = sqrt(11900 / 3600) = sqrt(3.306) = approximately 1.82 m2.
This calculator uses the Mosteller formula, published by R.D. Mosteller in the New England Journal of Medicine (1987): "Simplified Calculation of Body-Surface Area." Reference: Mosteller RD. N Engl J Med. 1987;317(17):1098. See NEJM: Simplified Calculation of Body-Surface Area.
Many chemotherapy agents are dosed in mg per m2 of BSA because drug clearance and toxicity correlate better with body surface area than with body weight alone for some agents. This relationship was described in studies dating to the 1950s and 1960s. However, the practice has been debated; some evidence suggests weight-based or fixed dosing works as well for certain agents. Dosing decisions belong to the treating oncologist or clinical pharmacist, not to a general calculator.
Several BSA formulas exist. The DuBois and DuBois formula (1916) is: BSA = 0.007184 x height_cm0.725 x weight_kg0.425. The Gehan and George formula (1970) is also commonly cited. These formulas produce similar results in adults of average size but can diverge in very small or very large patients. The Mosteller formula is widely used in current clinical practice because of its arithmetic simplicity.
See also: BMI Calculator for the standard CDC body mass index calculation, and LDL Cholesterol Calculator using the Friedewald equation.
The Mosteller formula is BSA (m2) = square root of (height in cm x weight in kg / 3600). It was published by R.D. Mosteller in the New England Journal of Medicine in 1987. It is one of the most widely used BSA formulas in clinical practice because of its simplicity.
Average BSA for adult men is approximately 1.9 m2 and for adult women approximately 1.6 m2, though the range varies considerably with height and weight. BSA is not categorized as normal or abnormal in the way BMI is; it is used mainly as a dosing parameter.
BSA is used to calculate doses of chemotherapy drugs and some other medications where dosing proportional to body size reduces toxicity. It is also used in some formulas for cardiac output and renal function. Dose calculations must be performed by a qualified prescriber or pharmacist.
No. Other commonly cited formulas include those by DuBois and DuBois (1916) and Gehan and George (1970). Different formulas can give slightly different results. The Mosteller formula is favored in many settings for its arithmetic simplicity.
No. Medication dosing based on BSA must be calculated and verified by a licensed healthcare provider or clinical pharmacist. This tool is for educational reference only.