BSA Calculator – Body Surface Area
Calculate Body Surface Area (BSA) using the Mosteller formula. Enter height and weight in convenient units and get the estimated BSA in m².
Calculate Body Surface Area
BSA Calculation Result
BSA is an estimated body-size parameter calculated from height and weight. The Mosteller equation is commonly used because it provides a simple calculation suitable for routine clinical and laboratory reference use.
BSA is not a direct measurement of actual body surface area, and different BSA equations may produce slightly different results.
What Is BSA?
Body Surface Area (BSA) is an estimated measurement of the total surface area of the human body. BSA is commonly expressed in square metres (m²).
BSA is calculated using body measurements such as height and weight. It is used in several areas of clinical medicine, including selected drug-dosing calculations, cardiac index calculations, and indexing certain physiological measurements.
Read the complete BSA Calculator: Body Surface Area Formula, Calculation & Clinical Uses article on LabProSuite.
Mosteller BSA Formula
The LabProSuite BSA Calculator uses the Mosteller formula to estimate Body Surface Area.
The formula uses height in centimetres and weight in kilograms and produces an estimated BSA in square metres.
How to Calculate BSA
- Enter the patient's weight.
- Select kg or lb.
- Enter the patient's height.
- Select cm, meter, or feet.
- Click Calculate BSA.
- The calculator converts the values into the required metric units.
- The Mosteller equation is applied.
- The estimated BSA is displayed in m².
BSA Calculation Example
Height: 170 cm
Weight: 70 kg
Calculation:
BSA ≈ 1.82 m²
Clinical Uses of BSA
Body Surface Area is used in several clinical and physiological applications.
- Selected medication dosing calculations
- Some chemotherapy dosing protocols
- Cardiac index calculations
- Indexing selected physiological measurements
- Clinical pharmacology and research
BSA and Medication Dosing
Some medications are prescribed using a dose expressed per square metre, such as mg/m². In those situations, BSA may be one component of the prescribed dose calculation.
This calculator provides a mathematical BSA estimate only. It should not be used by itself to determine or administer medication doses. Drug-specific prescribing information, treatment protocols, dose limits, patient factors, and professional clinical judgment must be followed.
BSA vs BMI
| Feature | BSA | BMI |
|---|---|---|
| Full name | Body Surface Area | Body Mass Index |
| Unit | m² | kg/m² |
| Main purpose | Estimate body surface area | Weight-for-height screening |
| Inputs | Height + Weight | Height + Weight |
Use the LabProSuite BMI Calculator to calculate Body Mass Index.
Mosteller Formula Advantages
The Mosteller equation is popular because it is relatively simple. It requires only height and weight and can be calculated easily without complicated mathematical operations.
However, several BSA equations exist. Mosteller, DuBois, Haycock, Gehan-George, and other equations can produce somewhat different values. When BSA is required for a specific clinical protocol, the formula specified by that protocol should be used.
Limitations of BSA
- BSA is an estimated value rather than a direct measurement.
- Different BSA equations can produce different results.
- BSA does not directly describe body composition.
- Extreme body size may affect the applicability of traditional equations.
- BSA should not be the sole basis for medication dosing decisions.
Frequently Asked Questions About BSA
What is BSA?
BSA stands for Body Surface Area. It is an estimated measurement of the body's surface area and is commonly expressed in square metres.
What formula does this calculator use?
This calculator uses the Mosteller formula: BSA = √[(height in cm × weight in kg) ÷ 3600].
What units can I use?
The calculator accepts weight in kilograms or pounds and height in centimetres, metres, or feet. Values are converted automatically before the calculation.
What is BSA measured in?
Body Surface Area is commonly expressed in square metres (m²).
What is an average adult BSA?
There is no single normal BSA value for every person because BSA varies according to height and weight. An often-used reference value for an average adult is approximately 1.73 m².
Is BSA the same as BMI?
No. BSA estimates body surface area, whereas BMI is a weight-for-height index primarily used for weight-status screening.
Why is BSA used in chemotherapy?
Some chemotherapy protocols use doses expressed per square metre of body surface area. The exact dosing method depends on the specific drug and treatment protocol.
Can BSA be calculated in children?
Yes. BSA equations can be used in pediatric patients, but medication dosing and clinical interpretation should follow appropriate pediatric and drug-specific protocols.
Can different BSA formulas give different results?
Yes. Different mathematical equations may produce slightly different BSA estimates.
BSA Calculator – Laboratory Reference
The LabProSuite BSA Calculator is designed as a convenient educational and laboratory reference tool for estimating Body Surface Area using the Mosteller equation.
For clinical use, always verify the appropriate formula and calculation requirements for the specific application.
Disclaimer
The LabProSuite BSA Calculator is provided for educational, laboratory reference, and calculation-support purposes only.
BSA is an estimated value and should not be used as the sole basis for diagnosis, treatment, or medication dosing. Medication doses should always be confirmed using the applicable prescribing information, clinical guidelines, and qualified healthcare professional judgment.
