Body Surface Area Calculator
The calculator below computes the total surface area of a human body, referred to as body surface area (BSA). Direct measurement of BSA is difficult, and as such many formulas have been published that estimate BSA. The calculator below provides results for some of the most popular formulas.
Result
Du Bois formula  2.09 m^{2}  22.47 ft^{2}  3,235 in^{2} 
Mosteller formula  2.12 m^{2}  22.78 ft^{2}  3,281 in^{2} 
Haycock formula  2.14 m^{2}  23.00 ft^{2}  3,312 in^{2} 
Gehan and George formula  2.13 m^{2}  22.96 ft^{2}  3,306 in^{2} 
Boyd formula  2.14 m^{2}  23.05 ft^{2}  3,319 in^{2} 
Fujimoto formula  2.03 m^{2}  21.82 ft^{2}  3,142 in^{2} 
Takahira formula  2.10 m^{2}  22.65 ft^{2}  3,261 in^{2} 
Schlich formula  1.98 m^{2}  21.32 ft^{2}  3,071 in^{2} 

Table of average BSAs
ft^{2}  m^{2}  
Newborn child  2.69  0.25 
Twoyearold child  5.38  0.5 
Tenyearold child  12.27  1.14 
Adult female  17.22  1.6 
Adult male  20.45  1.9 
BSA is often used in clinical purposes over body weight because it is a more accurate indicator of metabolic mass (the body's need for energy), where metabolic mass can be estimated as fatfree mass since body fat is not metabolically active.^{1} BSA is used in various clinical settings such as determining cardiac index (to relate a person's heart performance to their body size) or dosages for chemotherapy (a category of cancer treatment). While dosing for chemotherapy is often determined using a patient's BSA, there exist arguments against the use of BSA to determine medication dosages that have a narrow therapeutic index – the comparison of the amount of a substance necessary to produce a therapeutic effect, to the amount that causes toxicity.
Below are some of the most popular formulas for estimating BSA, and links to references for each for further detail on their derivations. The most widely used of these is the Du Bois formula, which has been shown to be effective for estimating body fat in both obese and nonobese patients, unlike body mass index. Where BSA is represented in m^{2}, W is weight in kg, and H is height in cm, the formulas are as follows:
1. Greenberg, JA., Boozer, CN. 1999. "Metabolic mass, metabolic rate, caloric restriction, and aging in male Fischer 344 rats." Elsevier 113(2000): 3748