Body Surface Area Calculator
Find your body surface area with the Mosteller and Du Bois formulas, the same measures clinicians use for drug dosing and burn assessment.
Awaiting Data
Enter your details and tap Calculate to see your results appear here.
Your result appears here.
What Body Surface Area Measures
Body surface area estimates the total outer area of your skin in square metres. Doctors lean on it more than weight alone because it tracks closely with how the body processes drugs and fluids.
Chemotherapy doses, burn-area calculations, and kidney-function scaling all use BSA. A larger surface area usually means a larger dose, so the number carries real clinical weight.
This tool is for general awareness. Never use it to set your own medication dose.
How to Use This Calculator
- Choose metric or US units.
- Enter your height.
- Enter your weight.
- Tap Calculate to see both Mosteller and Du Bois results.
The Formula Used
Du Bois: BSA (m²) = 0.007184 × height(cm)^0.725 × weight(kg)^0.425
- height
- Standing height in centimetres.
- weight
- Body weight in kilograms.
Mosteller is the simpler of the two and is the version most often used at the bedside. Du Bois, published in 1916, remains a trusted reference point.
Understanding Your Results
Tips for Accurate Results
- Measure height without shoes against a wall.
- Weigh yourself in light clothing at the same time of day.
- Use your current weight, not a past or goal number.
- Compare both formulas, since small differences are normal.
Frequently Asked Questions
Many body functions, including heart output and drug clearance, scale with surface area more closely than with weight, so BSA gives safer dosing.
Mosteller and Du Bois agree closely for most adults. Mosteller is favoured for its simplicity at the bedside.
No. BSA dosing is a clinical decision. Always let a qualified prescriber handle medication amounts.
Scientific References
- Mosteller, R. D. (1987). Simplified calculation of body-surface area. New England Journal of Medicine, 317(17), 1098.
- Du Bois, D., & Du Bois, E. F. (1916). A formula to estimate the approximate surface area if height and weight be known. Archives of Internal Medicine, 17, 863–871.
- Verbraecken, J., et al. (2006). Body surface area in normal-weight, overweight, and obese adults. Metabolism, 55(4), 515–524.