Body Surface Area (Mosteller) Calculator
Body surface area (BSA) is an important physiological parameter used in clinical medicine for dosing chemotherapy agents, calculating cardiac index, and adjusting kidney function measurements. The Mosteller formula (published in the New England Journal of Medicine, 1987) is: BSA (m2) = sqrt(height (cm) x weight (kg) / 3600). This calculator also supports US customary units (height in inches, weight in lbs) by converting internally before applying the formula. BSA values for this tool are informational; clinical dosing should always be performed under medical supervision.
Mosteller BSA formula
BSA (m2) = sqrt(height (cm) x weight (kg) / 3600)
Equivalent: BSA = sqrt(H x W) / 60
Source: Mosteller RD. "Simplified calculation of body-surface area." N Engl J Med. 1987;317(17):1098.
Clinical uses of BSA
- Chemotherapy dosing: many drugs dosed in mg/m2 (e.g., cisplatin, doxorubicin).
- GFR normalization: eGFR results are normalized to 1.73 m2 BSA for comparison.
- Cardiac index: cardiac output divided by BSA = cardiac index (L/min/m2).
- Burns assessment: total body surface area burned (TBSA%) guides fluid resuscitation.
- Pediatric dosing: BSA-based dosing is often preferred over weight-based for children.
Frequently asked questions
What is body surface area (BSA)?
Body surface area is the measured or estimated total surface area of a human body. It is used in medicine to dose chemotherapy drugs, calculate cardiac index, and set dialysis parameters. BSA is a better dosing basis than body weight for many drugs because it correlates with organ function and drug distribution volume.
What is the Mosteller formula?
The Mosteller formula is BSA (m2) = sqrt((height in cm x weight in kg) / 3600). It was published by R.D. Mosteller in 1987 in the New England Journal of Medicine and is one of the most widely used BSA formulas because of its simplicity and accuracy.
What is the average adult BSA?
The average BSA for an adult is approximately 1.7-1.9 m2. A commonly used value is 1.73 m2 (used as a standard for GFR normalization). Men typically have slightly higher BSA than women due to greater average height and weight.
How is BSA used in chemotherapy dosing?
Many chemotherapy regimens dose drugs in mg/m2 of BSA. For example, a dose of 100 mg/m2 for a patient with BSA of 1.75 m2 would be 175 mg. BSA-based dosing aims to standardize drug exposure across patients of different sizes.
Are there other BSA formulas?
Yes. The DuBois and DuBois formula (1916) is one of the oldest: BSA = 0.007184 x height^0.725 x weight^0.425. The Boyd formula and the Haycock formula are also used, particularly in pediatrics. Mosteller is preferred for clinical use due to its simplicity.
Official sources
- Mosteller RD, NEJM 1987: PMID 3657876 - Simplified calculation of body-surface area.
- NIH National Cancer Institute: Body Surface Area definition.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.