The Body Surface Area Calculator is a free tool that helps you calculate body surface area using the formula Du Bois: BSA = 0.007184 x weight^0.425 x height^0.725. Enter your values above and press Calculate to get body surface area instantly, with a full step-by-step breakdown.
What is the Body Surface Area Calculator?
The body surface area calculator is a free online tool that helps you calculate body surface area quickly and accurately. It applies the standard formula Du Bois: BSA = 0.007184 x weight^0.425 x height^0.725 to the values you enter and, when you press Calculate, displays the result together with a clear, step-by-step explanation of how the answer was reached.
Also known as: bsa calculator, bsa formula, body surface area.
How to use the Body Surface Area Calculator
- Enter weight and height.
- See your body surface area.
Formula used
The body surface area calculator is based on this formula:
Du Bois: BSA = 0.007184 x weight^0.425 x height^0.725Each term in the formula corresponds to one of the inputs explained below. The calculator performs the arithmetic for you and shows every step so you can check the working by hand if you wish.
Worked example
Suppose you enter 70kg, 170cm. The calculator works as follows:
| Inputs | 70kg, 170cm |
|---|---|
| Working | Du Bois formula |
| Result | BSA about 1.81 m2 |
Step-by-step calculation
- Apply the formula:
Du Bois: BSA = 0.007184 x weight^0.425 x height^0.725 - Substitute your values: Du Bois formula
- Read the result: BSA about 1.81 m2
Inputs explained
- Weight (kg) — the weight used in the calculation.
- Height (cm) — the height used in the calculation.
Understanding your result
- Body surface area — the calculated body surface area in m2.
Benefits and practical uses
The body surface area calculator saves time and removes the risk of manual errors when you need to calculate body surface area. It is useful for students, professionals and anyone who wants a fast, dependable answer. Results update the moment you press Calculate, work on any device, and can be copied or shared in a single click — and because the maths runs in your browser, your figures stay completely private.
Tips for an accurate result
- Keep all related inputs in the same units.
- Use the worked example above to confirm you are entering values in the right places.
- Review the assumptions below so the result fits your situation.
- Press Reset to clear everything and try a different scenario.
Common mistakes to avoid
- Entering values in the wrong unit (mismatched units give wrong answers).
- Leaving a required field empty — the calculator will ask you to fill it in.
- Treating the result as a diagnosis instead of a general guide.
Assumptions and limitations
- Du Bois & Du Bois formula.
Frequently asked questions
Why is BSA used?
Clinicians use BSA to dose certain medicines and assess metabolic needs.
How do I use the Body Surface Area Calculator?
Enter your values in the fields, then press the Calculate button to see the result. Use Reset to clear the form and start again. Nothing is calculated until you click Calculate.
What formula does the Body Surface Area Calculator use?
It uses the standard formula: Du Bois: BSA = 0.007184 x weight^0.425 x height^0.725. The full step-by-step working is shown with every result so you can verify it.
What information do I need to use the body surface area calculator?
You need: weight, height. Sensible example values are pre-filled so you can see how it works.
Is the Body Surface Area Calculator free to use?
Yes. Every DigiToolkit calculator is completely free, with no sign-up, no login and no usage limits.
Does the Body Surface Area Calculator work on mobile phones?
Yes. The calculator is mobile-first and works on phones, tablets and computers in any modern browser.
Do I need to install an app?
No. The body surface area calculator runs directly in your web browser — there is nothing to download or install.
Is my data private when I use this calculator?
Yes. All calculations run inside your browser. The numbers you enter are never uploaded to a server or shared with anyone.
How accurate is the Body Surface Area Calculator?
It uses the generally accepted formula for body surface area and computes to several decimal places. Results are accurate for the assumptions listed on this page.
Can I copy or share my result?
Yes. After calculating, use the Copy button to copy the result, or Share to copy the page link.
Why is nothing showing until I press Calculate?
By design, the calculator only computes when you press Calculate, so you can finish entering all your values first. Press Reset any time to clear everything.
What units does the Body Surface Area Calculator use?
It works with cm, kg. Keep your inputs in consistent units for an accurate result.