What is the Body Surface Area Calculator?
Body surface area is the total skin area of your body, used in medicine to dose some drugs and to compare cardiac and metabolic measures between people of different sizes.
How to use the Body Surface Area tool
- Enter Height and Weight.
- The result updates instantly as you type, or press Calculate.
- Use Try an example to see how it works, and Reset to start again.
Formula
Mosteller formula: BSA (m²) = √(height in cm × weight in kg ÷ 3600).
Worked example
With height 175 cm, weight 70 kg, the body surface area comes to 1.84 m².
Frequently asked questions
What is a normal BSA?
The average adult has a BSA of about 1.7 m², with men slightly higher than women.
Should I use this for medication doses?
No. Clinicians calculate doses. This tool is for general information.
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Checked by Calcovate · Formula tested against worked examples · Updated 7 Nov 2026 · How we check our calculators. General information only, not financial or medical advice.