Body Surface Area Calculator
BSA by Mosteller, Du Bois and Haycock formulas.
Enter your values
Choose one of: Metric (kg, cm), Imperial (lb, in).
Enter the weight you are working with.
Enter the height you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- BSA (Mosteller)
- 1.845 m²
- BSA (Du Bois)
- 1.848 m²
- BSA (Haycock)
- 1.847 m²
Working
- 1Mosteller: √(175 × 70 ÷ 3600) = 1.845 m²
Quick answer
Body surface area is used for chemotherapy dosing and cardiac index; the Mosteller formula is √(height cm × weight kg ÷ 3600).
BSA = √(cm × kg ÷ 3600)
At a glance
| What it does | BSA by Mosteller, Du Bois and Haycock formulas. |
|---|---|
| Category | Health |
| Inputs needed | Units, Weight, Height |
| Main output | BSA (Mosteller) |
| Formula | BSA = √(cm × kg ÷ 3600) |
| Cost | Free — no sign-up, no download |
How to use the Body Surface Area Calculator
- 1Choose your units.
- 2Enter weight and height.
- 3Compare the three standard formulas.
Inputs explained
- Units
- Choose one of: Metric (kg, cm), Imperial (lb, in).
- Weight
- Enter the weight you are working with.
- Height
- Enter the height you are working with.
Worked example
Using the values the calculator loads with:
Inputs
- UnitsMetric (kg, cm)
- Weight70
- Height175
Results
- BSA (Mosteller)1.845 m²
- BSA (Du Bois)1.848 m²
- BSA (Haycock)1.847 m²
- Mosteller: √(175 × 70 ÷ 3600) = 1.845 m²
Frequently asked questions
Which formula do hospitals use?
Mosteller is the most common because it is simple and agrees closely with Du Bois across normal ranges.
Why is BSA used for dosing?
It correlates better with metabolic rate and blood volume than weight alone, which matters for narrow-therapeutic-index drugs.
What do I need to enter into the Body Surface Area Calculator?
Just 3 values: units, weight, height. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Body Surface Area Calculator work out the answer?
Body surface area is used for chemotherapy dosing and cardiac index; the Mosteller formula is √(height cm × weight kg ÷ 3600). It applies the formula BSA = √(cm × kg ÷ 3600) and shows the working so you can check each step by hand.
Is the Body Surface Area Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.