Body Surface Area Calculator
Estimate adult body surface area with Mosteller or Du Bois, compare both methods and inspect height-weight sensitivity in square metres.
Surface area estimates workspace
Adult area estimate; no treatment dosing
Your surface area estimate
1.91 m² · estimated BSA
Mosteller primary method
Full result table
| Body mass (kg) | Mosteller m² | Du Bois m² |
|---|---|---|
| 60 | 1.707825 | 1.730945 |
| 67.5 | 1.811422 | 1.819797 |
| 75 | 1.909407 | 1.903137 |
| 82.5 | 2.002602 | 1.981809 |
| 90 | 2.09165 | 2.056468 |
Adult height-weight estimates, not a direct skin-surface measurement. Method difference is not a confidence interval. No medication, fluid or treatment dose is calculated. Paediatric sizing and unusual body proportions require appropriate professional methods.
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How to use Body Surface Area Calculator
- Enter height in centimetres and body mass in kilograms.
- The bar chart holds the input measurements fixed and compares Mosteller with Du Bois.
- BSA can appear in clinical calculations, but this page returns area only.
Worked example
At 175 cm and 75 kg, Mosteller gives sqrt(13125/3600) = 1.909407 m². Du Bois is displayed alongside it from the same measurements.
Formula, accuracy & limitations
Mosteller BSA(m²) = sqrt(height(cm) × weight(kg) / 3600). Du Bois BSA(m²) = 0.007184 × height(cm)^0.725 × weight(kg)^0.425.
Adult height-weight estimates, not a direct skin-surface measurement. Method difference is not a confidence interval. No medication, fluid or treatment dose is calculated. Paediatric sizing and unusual body proportions require appropriate professional methods.
These outputs use the stated model and your supplied inputs. A mathematically consistent model can still differ from personal measurements. Scenario curves and formula comparisons are not statistical confidence intervals.
Source and method context ↗Use adult metric measurements
Enter height in centimetres and body mass in kilograms. Choose which equation should appear as the main estimate. Both formulas use the same measurements, and neither selector changes the units or automatically converts a number typed in pounds.
Compare the two methods in square metres
The bar chart holds the input measurements fixed and compares Mosteller with Du Bois. Their difference reflects model choice, not an extra amount of skin. The sensitivity curve then varies body weight within the supported input range while holding height fixed.
Keep area separate from treatment decisions
BSA can appear in clinical calculations, but this page returns area only. It does not translate that area into medication dosing or an infusion plan. The methods are approximations and their suitability depends on the person and context, especially outside the adult range supported here.
Use an exact reference example for a unit check
Height 180 cm and mass 80 kg give a Mosteller area of exactly 2 m² because 180 × 80 / 3600 equals four. This is a convenient arithmetic check when comparing implementations. The Du Bois result can differ because it uses fractional powers and a different coefficient. Keep the height in centimetres for both equations and retain full numerical precision internally; rounding height, mass or intermediate powers too early creates avoidable differences without improving the physiological estimate.
Frequently asked questions
Why do Mosteller and Du Bois differ?
They use different mathematical relationships between height and mass. Both estimate the same area quantity; a difference does not identify which is individually correct.
Does m² mean my height squared?
The output is estimated body surface area in square metres. Although height is part of the calculation, BSA is not simply height multiplied by itself.
Can this calculate a drug dose?
There is no dose input or dose output. Treatment calculations need the correct clinical protocol and professional review.
Can I use this for a child?
The interface is scoped to adult height and mass ranges. It does not claim paediatric validation or substitute for a suitable paediatric method.
