Body Surface Area Calculator
Body surface area (BSA) is used to dose some medicines, including many chemotherapy drugs, and to index heart and kidney measurements to body size. This uses the Mosteller formula and shows DuBois for comparison.
Source: Mosteller RD. Simplified calculation of body-surface area. N Engl J Med 1987;317(17):1098. (doi:10.1056/NEJM198710223171717); Redlarski G, Palkowski A, Krawczuk M. Body surface area formulae: an alarming ambiguity. Sci Rep 2016;6:27966. (doi:10.1038/srep27966); Du Bois D, Du Bois EF. A formula to estimate the approximate surface area if height and weight be known. Arch Intern Med 1916;17:863-871. Reprinted in Nutrition 1989;5(5):303-311.
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BSA formulas
Mosteller: BSA (m²) = √(height in cm × weight in kg ÷ 3600)
DuBois: BSA (m²) = 0.007184 × weight^0.425 × height^0.725 (weight in kg, height in cm)
Mosteller, published in 1987, is the simpler of the two and the main result here. DuBois dates from 1916 and is still used in many references.
Worked example
Height 170 cm, weight 70 kg:
- Mosteller: √(170 × 70 ÷ 3600) = 1.82 m²
- DuBois: 1.81 m²
BSA chart (Mosteller)
| Height | 50 kg | 60 kg | 70 kg | 80 kg | 90 kg | 100 kg |
|---|---|---|---|---|---|---|
| 150 cm (59 in) | 1.44 | 1.58 | 1.71 | 1.83 | 1.94 | 2.04 |
| 160 cm (63 in) | 1.49 | 1.63 | 1.76 | 1.89 | 2.00 | 2.11 |
| 170 cm (67 in) | 1.54 | 1.68 | 1.82 | 1.94 | 2.06 | 2.17 |
| 180 cm (71 in) | 1.58 | 1.73 | 1.87 | 2.00 | 2.12 | 2.24 |
| 190 cm (75 in) | 1.62 | 1.78 | 1.92 | 2.05 | 2.18 | 2.30 |
Why formulas disagree
Many BSA formulas have been published, and a 2016 review found they can give noticeably different results for the same person. When BSA is used to dose a medicine, the prescriber’s chosen formula is the one that counts, so check which one your care team uses.
FAQs
What is a normal body surface area?
There is no “normal” BSA in the health sense; it simply scales with height and weight. For reference, a person 170 cm tall weighing 70 kg has a BSA of about 1.8 m².
Which BSA formula is most accurate?
No single formula is best for everyone. This calculator shows Mosteller and DuBois side by side so you can see how far apart they are for your height and weight.
What is BSA used for?
Dosing some medicines, including many chemotherapy drugs, and adjusting measurements such as kidney function for body size. eGFR, for example, is reported per 1.73 m² of BSA.