About Body Surface Area

The calculator 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 provides results for some of the most popular formulas.

Table of average BSAs

	ft²	m²
Newborn child	2.69	0.25
Two-year-old child	5.38	0.5
Ten-year-old child	12.27	1.14
Adult female	17.22	1.6
Adult male	20.45	1.9

Clinical Importance

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). Metabolic mass can be estimated using fat-free mass, where fat-free mass is all of a person's body mass that does not include fat. This includes bones, tendons, inner organs, muscles, blood, nerves, and more.

BSA is also used in various other clinical settings, such as determining cardiac index (to relate a person's heart performance to their body size) or most commonly, dosages for chemotherapy (a category of cancer treatment).

BSA Formulas

Du Bois formula

Du Bois D, Du Bois EF (Jun 1916). "A formula to estimate the approximate surface area if height and weight be known". Archives of Internal Medicine 17 (6): 863-71.

Mosteller formula

Mosteller RD. "Simplified calculation of body-surface area". N Engl J Med 1987; 317:1098.

Haycock formula

Haycock GB, Schwartz GJ, Wisotsky DH "Geometric method for measuring body surface area: A height-weight formula validated in infants, children and adults" J Pediatr 1978, 93:62-66.

Gehan and George formula

Gehan EA, George SL, Cancer Chemother Rep 1970, 54:225-235

Boyd formula

Boyd, Edith (1935). The Growth of the Surface Area of the Human Body. University of Minnesota.

Fujimoto formula

Fujimoto S, Watanabe T, Sakamoto A, Yukawa K, Morimoto K. Studies on the physical surface area of Japanese. 18. Calculation formulae in three stages over all ages. Nippon Eiseigaku Zasshi 1968;5:443-50.

Takahira formula

Fujimoto S, Watanabe T, Sakamoto A, Yukawa K, Morimoto K. Studies on the physical surface area of Japanese. 18. Calculation formulae in three stages over all ages. Nippon Eiseigaku Zasshi 1968;5:443-50.

Schlich formula

Schlich E, Schumm M, Schlich M: "3-D-Body-Scan als anthropometrisches Verfahren zur Bestimmung der spezifischen Korperoberflache". Ernahrungs Umschau 2010;57:178-183