Body Surface Area (BSA) is a measure of the total area on the outside of a person's body. It is often used in medicine for dosing certain medications and for estimating the amount of intravenous fluid a burn victim might need. Many web sites have on-line calculators to determine BSA and this web site is no exception (click on the "Program" link, above).
Also offered are two PDF files which contain body surface area (BSA) measurements that can be used to make a quick estimation of a patient's BSA. The files are probably difficult to use for on-screen viewing, but if they are printed they can serve as a useful reference. A potential way to use them would be to print them both out, place them back-to-back, and laminate them to keep as a resource that could be used for a quick reference in an emergency. The two tables cover the range of 5 to 96 kg and 70 to 200 cm. These two files, as well as a small calculator program for the Macintosh, can be found by following the "Download" link, anove.
The formula used for the calculations is:
BSA = sqrt(weight [kg] * height [cm] / 3600)†
†Mosteller RD: Simplified Calculation of Body Surface Area. N Engl J Med 1987 Oct 22;317(17):1098 (letter)