BSA calculator form
The input area uses three columns on large screens, two on medium screens, and one on mobile screens.
Example data table
| Case | Height (cm) | Weight (kg) | DuBois BSA (m²) | Mosteller BSA (m²) | BMI (kg/m²) |
|---|---|---|---|---|---|
| Adult A | 170 | 70 | 1.810 | 1.818 | 24.22 |
| Adult B | 160 | 55 | 1.563 | 1.563 | 21.48 |
| Pediatric A | 110 | 18 | 0.741 | 0.742 | 14.88 |
| Pediatric B | 95 | 14 | 0.599 | 0.608 | 15.51 |
Formula used
The primary body surface area calculation on this page uses the DuBois and DuBois equation with height in centimeters and weight in kilograms.
BSA = 0.007184 × Weight0.425 × Height0.725
For comparison, the page also calculates Mosteller and Haycock values. These do not replace the main output, but they help users see method sensitivity.
BSA = √((Height × Weight) / 3600)
BSA = 0.024265 × Weight0.5378 × Height0.3964
Optional extensions
Estimated dose = BSA × entered dose intensity in mg/m²
Estimated fluid = BSA × entered fluid intensity in mL/m²
How to use this calculator
- Enter a patient label if you want named output.
- Type height and choose centimeters, meters, or inches.
- Type weight and choose kilograms or pounds.
- Add dose intensity if a medication order uses mg/m².
- Add fluid intensity if a protocol uses mL/m².
- Select the number of decimal places you prefer.
- Press Calculate BSA to display the result above the form.
- Use the export buttons to save CSV or PDF output.
Frequently asked questions
1. What does BSA mean in medicine?
BSA means body surface area. It estimates external body size from height and weight. Clinicians often use it for dose checks, fluid calculations, and physiologic comparisons.
2. Why use the DuBois formula?
The DuBois equation is a classic BSA method. It remains widely recognized and offers a consistent reference point when height and weight are known.
3. Can this calculator accept inches and pounds?
Yes. The form converts inches to centimeters and pounds to kilograms before applying the DuBois equation. This keeps the internal calculation consistent.
4. Why are Mosteller and Haycock shown too?
Those values help you compare formula sensitivity. Small differences between methods are common, especially across pediatric and adult body sizes.
5. Is BSA the same as BMI?
No. BSA estimates body surface area in square meters. BMI relates body mass to height squared and is often used for weight status screening.
6. Can I use the result for drug dosing?
The calculator can estimate a total dose from an entered mg/m² value. Final prescribing decisions should still follow clinical protocols and professional review.
7. Why does the page include a graph?
The graph shows how BSA changes as weight shifts while height stays fixed. It makes the scale of change easier to interpret than a single number alone.
8. Does this tool replace medical judgment?
No. It is a calculation aid. Clinical interpretation, medication ordering, pediatric adjustments, and protocol compliance still require qualified medical review.