BSA Calculator
Created by: James Porter Medical Calculator Specialist
Last updated:
Body surface area (BSA) is usually calculated with the Mosteller formula: BSA = √(height in cm × weight in kg ÷ 3600). A person 170 cm tall weighing 70 kg has a BSA of 1.82 m². The calculator below shows Mosteller, Du Bois, Haycock and Gehan and George results together and can multiply a dose in mg/m² by the BSA.
Body Surface Area (BSA) Calculator
Mosteller, Du Bois, Haycock and Gehan and George formulas side by side.
BSA chart by height and weight (Mosteller)
Body surface area in m² for adult heights and weights.
| Height | 50 kg 110 lb | 60 kg 132 lb | 70 kg 154 lb | 80 kg 176 lb | 90 kg 198 lb | 100 kg 220 lb | 110 kg 243 lb |
|---|---|---|---|---|---|---|---|
| 150 cm (4′11″) | 1.44 | 1.58 | 1.71 | 1.83 | 1.94 | 2.04 | 2.14 |
| 155 cm (5′1″) | 1.47 | 1.61 | 1.74 | 1.86 | 1.97 | 2.07 | 2.18 |
| 160 cm (5′3″) | 1.49 | 1.63 | 1.76 | 1.89 | 2.00 | 2.11 | 2.21 |
| 165 cm (5′5″) | 1.51 | 1.66 | 1.79 | 1.91 | 2.03 | 2.14 | 2.25 |
| 170 cm (5′7″) | 1.54 | 1.68 | 1.82 | 1.94 | 2.06 | 2.17 | 2.28 |
| 175 cm (5′9″) | 1.56 | 1.71 | 1.84 | 1.97 | 2.09 | 2.20 | 2.31 |
| 180 cm (5′11″) | 1.58 | 1.73 | 1.87 | 2.00 | 2.12 | 2.24 | 2.35 |
| 185 cm (6′1″) | 1.60 | 1.76 | 1.90 | 2.03 | 2.15 | 2.27 | 2.38 |
| 190 cm (6′3″) | 1.62 | 1.78 | 1.92 | 2.05 | 2.18 | 2.30 | 2.41 |
BSA formulas
Height (H) in centimeters, weight (W) in kilograms, BSA in square meters.
- Mosteller: BSA = √(height × weight ÷ 3600)
- Du Bois: BSA = 0.007184 × W^0.425 × H^0.725
- Haycock: BSA = 0.024265 × W^0.5378 × H^0.3964
- Gehan and George: BSA = 0.0235 × W^0.51456 × H^0.42246
Worked example
For a patient 180 cm tall weighing 75 kg: Mosteller gives √(180 × 75 ÷ 3600) = √3.75 = 1.94 m², Du Bois gives 1.94 m², Haycock 1.94 m² and Gehan and George 1.94 m².
Frequently Asked Questions
How do you calculate body surface area?
The most common method is the Mosteller formula: BSA (m²) = √(height in cm × weight in kg ÷ 3600). A person 170 cm tall weighing 70 kg has a BSA of √(170 × 70 ÷ 3600) = √3.306 = 1.82 m².
Which BSA formula should I use?
Mosteller is the simplest and is the default in many hospital systems and online clinical calculators. Du Bois (1916) is the oldest and still widely used. Haycock was validated in infants and children as well as adults. For typical adults the formulas agree within a few percent; follow your institution’s protocol when dosing.
What is a normal BSA for an adult?
Average adult BSA is about 1.9 m² for men and 1.6 m² for women. Most adults fall between roughly 1.5 and 2.2 m².
How is BSA used for chemotherapy dosing?
Many chemotherapy drugs are prescribed in mg per m². The dose is the prescribed amount multiplied by BSA: 75 mg/m² for a patient with a BSA of 1.8 m² is 135 mg. Dose limits, capping and adjustments for obesity follow the treatment protocol, not the formula alone.
How do I calculate BSA in pounds and inches?
The Mosteller formula in U.S. units is √(height in inches × weight in pounds ÷ 3131). A 5′10″ (70 in), 165 lb adult has a BSA of √(70 × 165 ÷ 3131) = 1.92 m². The calculator converts units for you.
What else is BSA used for?
Cardiac index (cardiac output ÷ BSA), indexing heart chamber sizes on echocardiograms, estimating glomerular filtration rate per 1.73 m², and calculating fluid and burn treatment needs.
Sources and References
- Mosteller RD. Simplified calculation of body-surface area. N Engl J Med. 1987;317(17):1098.
- 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(6):863–871.
- Haycock GB, Schwartz GJ, Wisotsky DH. Geometric method for measuring body surface area: a height-weight formula validated in infants, children, and adults. J Pediatr. 1978;93(1):62–66.
- Gehan EA, George SL. Estimation of human body surface area from height and weight. Cancer Chemother Rep. 1970;54(4):225–235.
For general information. Clinical dosing should follow the prescriber’s protocol.