Body Surface Area Calculator
Body surface area is used in medicine for dosing certain drugs and for clinical calculations. The Mosteller formula is widely used and easy to calculate from height and weight.
| Height | cm |
| Weight | kg |
| Use imperial units |
Result
Your result will appear here.
How it works
The Mosteller formula estimates total body surface area from height and weight. It's the most common formula in clinical practice because it's simple and reasonably accurate for most adults.
Formula
BSA (m²) = sqrt((height in cm × weight in kg) ÷ 3600)
Worked example
A person 175 cm tall weighing 70 kg: (175×70)=12250, 12250/3600≈3.4028, sqrt≈1.845 m².
Assumptions
Mosteller formula is an estimate. Different formulas (DuBois, Haycock) give slightly different results. This calculator is for informational purposes only - not for medical decision making.
Reading the result
Normal adult BSA is roughly 1.7 m² for men and 1.6 m² for women, but it varies with body size.
For general information only. Not a substitute for professional medical advice.
How to use the Body Surface Area Calculator
It takes a few seconds, and every figure is calculated in your browser.
- Enter your height.
- Enter your weight.
- Choose metric or imperial units.
- Press Calculate — the result appears in the dark panel beside the form.
- Use Copy, CSV, Share or Print under the result if you want to keep it.
Body Surface Area Calculator — frequently asked questions
What formula does the Body Surface Area Calculator use?
BSA (m²) = sqrt((height in cm × weight in kg) ÷ 3600)
How does the Body Surface Area Calculator work?
The Mosteller formula estimates total body surface area from height and weight. It's the most common formula in clinical practice because it's simple and reasonably accurate for most adults.
What assumptions and limitations should I know about?
Mosteller formula is an estimate. Different formulas (DuBois, Haycock) give slightly different results. This calculator is for informational purposes only - not for medical decision making.
Can you walk through a worked example?
A person 175 cm tall weighing 70 kg: (175×70)=12250, 12250/3600≈3.4028, sqrt≈1.845 m².
Last updated 10 November 2026 · Formula, worked example and assumptions are documented above, and every result is calculated in your browser.