The Body Surface Area Calculator contains all Height and Weightof the major formulas for determining a person's body surface area (BSA) using different units (centimeters, feet or inches and kilograms or pounds). It includes the Mosteller, DuBois, Haycock, Gehan and George, Boyd, Fujimoto,Takahira, Schlich, Wang and Hihara and Costeff equations. It also includes the average (numeric mean) BSA for different demographics including neonatal (newborn), children of age 2, 9, and 10, children in the 12 to 13 year old range, and the mean BSA for men and women.
In physiology and medicine, the body surface area (BSA)1 is the measured or calculated surface area of a human body. For many clinical purposes BSA is a better indicator of metabolic mass than body weight because it is less affected by abnormal adipose mass. Estimation of BSA is simpler than many measures of volume.
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This calculator includes numerous equations that provide estimates for the body surface area. Each equation requires some combination of height, weight, and gender. The table to the right shows which methods employ which combinations of height (H), weight (W) and Gender.
The equations also include a Unified BSA formula by Wang and Hihara for the body surface area of humans and animals based on volume and length.
The BSA Compare formula lets you enter a body surface area and choose a demographic mean for comparison. In this way, you can compare an actual BSA from a patient to their demographic mean which may effect dosage. (See Demographic Means below).
The mean (average) body surface areas for different demographics are listed below.
There have been several important critiques of the use of BSA in determining the dosage of medications with a narrow therapeutic index2, such as chemotherapy. Typically there is a 4–10 fold variation in drug clearance between individuals due to differing the activity of drug elimination processes related to genetic and environmental factors. This can lead to significant overdosing and even more perniciously to underdosing (and increased risk of disease recurrence). It is also thought to be a distorting factor in Phase I and II trials that may result in potentially helpful medications being prematurely rejected.3 The trend to personalized medicine is one approach to counter this weakness.