Use these nursing scenarios to sanity-check the formula, then load the same values back into the calculator with one click.
Adult
This is the standard Mosteller example for an average-sized adult patient.
This is the same example many nursing and oncology references use to teach the Mosteller method.
Imperial Units
Many bedside measurements in the U.S. start in inches and pounds, so the first step is unit conversion.
This example shows why accurate inch-to-cm and lb-to-kg conversion matters before BSA dosing.
Pediatric
Smaller patients can have a much lower BSA even when they look proportionally similar to adults.
BSA-based dosing becomes especially important when adult-size fixed doses would be unsafe.
The Mosteller formula is the most widely used method for calculating body surface area in clinical settings. It requires only height and weight, making it practical for bedside calculations.
BSA (m²) = √((Height cm × Weight kg) / 3600)
Enter the patient's height and weight above to instantly calculate body surface area using the Mosteller formula. BSA is used to individualize drug dosing for chemotherapy, immunosuppressants, and other narrow-therapeutic-index medications where a fixed adult dose would be unsafe.
A patient is 170 cm tall and weighs 70 kg. Calculate the BSA using the Mosteller formula.
A typical adult BSA ranges from 1.5 to 2.2 m².
BSA correlates more closely with physiological parameters like cardiac output, blood volume, and glomerular filtration rate than body weight alone. This is why chemotherapy protocols, some antibiotic dosing guides, and fluid resuscitation formulas reference BSA rather than weight.
BSA correlates more closely with physiological parameters like cardiac output, blood volume, and renal function than body weight alone. This makes it a better predictor of how the body will process certain medications, particularly narrow therapeutic index drugs.
The Mosteller formula calculates BSA as the square root of (height in cm multiplied by weight in kg, divided by 3600). It was proposed by Dr. R.D. Mosteller in 1987 and is favored for its simplicity while maintaining accuracy comparable to more complex formulas.
Yes, other common formulas include Du Bois & Du Bois (1916), Haycock (1978), and Gehan & George (1970). The Mosteller formula is preferred in most clinical settings because it is simpler to calculate and produces results very close to the more complex formulas.
The Mosteller equation is BSA (m²) = sqrt((Height in cm × Weight in kg) / 3600). It is widely used because it is easy to calculate and gives results close to more complex BSA equations.
Yes. The Mosteller formula expects height in centimeters and weight in kilograms. If the patient is measured in inches or pounds, convert those values first so the formula is applied correctly.
BSA appears most often in chemotherapy dosing, some immunosuppressant regimens, cardiac index calculations, and other situations where body size needs to normalize a dose or physiologic measurement more precisely than body weight alone.
Reference:
Mosteller RD. Simplified calculation of body-surface area. N Engl J Med. 1987;317(17):1098. https://doi.org/10.1056/NEJM198710223171717