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Body Surface Area Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Body surface area (Mosteller)
1.818
- BSA (Du Bois)
- 1.810
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Body Surface Area Calculator
The Body Surface Area Calculator works out your body surface area (mosteller), along with 1 related figure in an instant. Enter weight and height and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the weight.
- Enter the height.
- Read off your body surface area (mosteller), together with bsa (du bois) — the calculator updates automatically, with no button to press.
Formula
The Body Surface Area Calculator uses the formula:
Body surface area (Mosteller) = √(Height × Weight ÷ 3600)
Worked example
For example, with weight of 70 kg and height of 170 cm, the body surface area (mosteller) is 1.818.
| Weight | 70 kg |
|---|---|
| Height | 170 cm |
| Body surface area (Mosteller) | 1.818 |
|---|---|
| BSA (Du Bois) | 1.810 |
Results are estimates for educational use, not professional advice.
Key terms explained
- Body surface area
- The total external area of the body, used in medicine to scale drug doses (BSA).
- Surface area
- The total area of all the outer faces of a three-dimensional object.
- Area
- The amount of two-dimensional space a shape covers, measured in square units.
Frequently asked questions
Body surface area (BSA) is the total area of the outside of the body, in square metres. It is widely used in medicine to scale drug doses, especially in chemotherapy.
The Mosteller formula is √(height in cm × weight in kg ÷ 3600). For 170 cm and 70 kg it gives about 1.82 m². The Du Bois formula is an older alternative shown alongside.
Several BSA formulas exist and give slightly different values. Mosteller is simple and popular; Du Bois is the classic clinical formula. They usually agree closely.
It is for general information only. Clinical dosing should always be done by a qualified professional using the method their guidelines specify.
Enter the weight. Enter the height. Read off your body surface area (mosteller), together with bsa (du bois) — the calculator updates automatically, with no button to press.
Related guides
Body Surface Area Table: Body surface area (Mosteller) by Weight
Reference table of body surface area (mosteller) for Body Surface Area across a range of weight values — exact, engine-computed figures you can read off at a glance.
How to Calculate Body Surface Area: Formula, Steps & Examples
Learn how to calculate Body Surface Area — the formula explained step by step, with worked examples and a free calculator to check your answer.