Body surface area


Body surface area: BSA. The total surface area of the human body. The body surface area is used in many measurements in medicine, including the calculation of drug dosages and the amount of fluids to be administered IV.

A number of different formulas have been developed over the years to calculate the body surface area and they give slightly different results. The most commonly used formula now is that of Mosteller, published in 1987 in The New England Journal of Medicine. According to Mosteller’s “simplified calculation of body-surface area In metric terms” the body surface area = the square root of product of the weight in kg times the height in cm divided by 3600.

The “normal” body surface area is generally taken to be 1.7 m2 but, in actual fact, the body surface area depends on more than just height and weight. Other influential factors include the age and gender of the individual. For example:

Average body surface area for adult men: 1.9 m2
Average body surface area for adult women: 1.6 m2
Average body surface area for children (9 years): 1.07 m2
Average body surface area for children (10 years): 1.14 m2
Average body surface area for children (12-13 years): 1.33 m2

Body surface area is used for a determining other medical measures. As examples, renal function is measured by the glomerular filtration rate (GFR) which is calculated in regard to the body surface area. The cardiac index is a measure of cardiac output divided by the body surface area, giving a better approximation of the required cardiac output. Chemotherapy and pharmacotherapies are often dosed according to the patient’s body surface area. Glucocorticoid dosing is also expressed in terms of body surface area for calculating maintenance doses or to compare high dose use with maintenance requirement.

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

Read Also:

  • Body type

    Body type: A somewhat old-fashioned term used to classify the human shape into three primary types: ectomorphic, mesomorphic, or endomorphic.

  • Bodywork

    Bodywork: Any of a number of therapeutic or simply relaxing practices that involve the manipulation, massage, or regimented movement of body parts. Examples include massage, craniosacral therapy, and Pilates. Bodywork may be used as an adjunct to medical treatment, or it may be prescribed as a form of physical therapy for certain conditions.

  • Body, ciliary

    Body, ciliary: Part of the eye, the ciliary body is a thin vascular (blood vessel-filled) middle layer of the eye that is situated between the sclera (the white of the eye) and the retina (the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve […]

  • Boerhaave's syndrome

    Boerhaave’s syndrome: Spontaneous tearing and rupture of the esophagus. Typically, Boerhaave’s syndrome requires an operation for repair.

  • Bogorad's syndrome

    Bogorad’s syndrome: Named after the Russian neuropathologist who described the syndrome of crocodile tears. See: Crocodile tears syndrome.


Disclaimer: Body surface area definition / meaning should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional. All content on this website is for informational purposes only.