Body Surface Area
Calculate BSA (Mosteller, Du Bois) for dosing.
✓ Professional standard Uses internationally recognised clinical formulas — WHO, NHS, CDC, the U.S. Navy method and Mifflin-St Jeor — for screening-grade estimates.
Body Surface Area is a free online medical & health tool from Toolinza. Calculate BSA (Mosteller, Du Bois) for dosing. It runs entirely in your browser — your data is never uploaded — needs no signup, and works on any device. Toolinza offers 293+ free tools used by people across the UK, USA, Canada, Australia, the EU, India, Pakistan, the Middle East and worldwide.
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About the Body Surface Area
Body Surface Area (BSA) is used across medicine — especially for calculating drug doses and assessing certain treatments — because it often reflects the body's needs better than weight alone. It is a standard clinical measure, and knowing it can be useful for students and patients alike.
This Body Surface Area calculator gives your BSA using the widely used Mosteller and Du Bois formulas, from your height and weight.
How to use the Body Surface Area
- Enter your height.
- Enter your weight.
- Choose metric or imperial units.
- See your BSA from the Mosteller and Du Bois formulas.
Key features of the Body Surface Area
- Uses the Mosteller and Du Bois formulas
- A standard clinical measure
- Relevant to dosing and assessment
- Metric and imperial units
- Private — calculated in your browser
How the Body Surface Area works
This calculator applies standard, peer-reviewed formulas used by health professionals and public-health bodies worldwide. Depending on the metric, that includes the World Health Organization (WHO) classification, NHS and CDC guidance, the Mifflin-St Jeor equation for metabolic rate, and the U.S. Navy method for body composition. Inputs are converted between metric and imperial units using exact factors so results are consistent whichever system you use.
All calculations are performed in your browser, so the health information you enter is never sent anywhere.
Tips & best practices
- The Mosteller formula is popular because it is simple and accurate enough for most clinical uses.
- BSA-based dosing is a clinical decision — this tool is for understanding and education, not for self-medicating.
- Different formulas give slightly different values, which is why clinicians pick one and apply it consistently.
Standards & accuracy
Uses internationally recognised clinical formulas — WHO, NHS, CDC, the U.S. Navy method and Mifflin-St Jeor — for screening-grade estimates.
Important: these tools provide screening-grade estimates for general information and education only. They are not a medical diagnosis and do not replace professional advice. Always consult a qualified healthcare provider before making health decisions.
Who uses the Body Surface Area?
- Understanding a measure used in dosing
- Medical and nursing study
- Comparing the common BSA formulas
- Health education
Privacy & security
The Body Surface Area runs entirely inside your web browser. Your data — whether that is a file, figures or text — is processed on your own device and is never uploaded to a server, stored or shared. There is no signup and no account, so you can use it as often as you like while keeping full control of your information. This makes it a safe choice even for confidential and sensitive work.
Why choose Toolinza?
- 100% free — no hidden charges, watermarks or usage caps.
- Private & secure — your data stays on your device.
- Standards-compliant — accurate results suitable for the UK, USA, Canada, Australia, EU, India, Pakistan, the Middle East and worldwide.
- Works everywhere — desktop, tablet and mobile.
Frequently asked questions
BSA is used in medicine to calculate certain drug doses and to assess some treatments, because it can reflect the body's needs better than weight alone.
The Mosteller formula is widely used for its simplicity and accuracy, while Du Bois is a long-standing standard. The calculator shows both, as clinicians choose one and apply it consistently.
No. Dosing is a clinical decision made by a qualified professional. This calculator is for understanding and education only.
Yes. The Body Surface Area is completely free with no signup, no watermarks and no usage limits. Toolinza is supported by unobtrusive advertising so every tool stays free.
Absolutely. This tool runs entirely in your browser — your data and files are never uploaded to any server, so everything stays private on your own device.
No. The Body Surface Area works instantly in any modern web browser on desktop, tablet and mobile — Windows, macOS, Linux, Android and iOS.