Body Surface Area Calculator
Calculate your body surface area using height and weight. This BSA calculator uses the Mosteller formula to estimate body surface area in square meters.
Add your height and weight to estimate your body surface area.
What Is Body Surface Area?
Body surface area, or BSA, is an estimate of the total surface area of the human body. It is usually expressed in square meters. BSA is commonly used in medical, pharmacy, and clinical settings because it can sometimes reflect body size better than body weight alone.
Body Surface Area Formula
This calculator uses the Mosteller formula. It is one of the simplest and most commonly used BSA formulas.
| Formula | Calculation |
|---|---|
| Mosteller Formula | BSA = √((height in cm × weight in kg) ÷ 3600) |
| Du Bois Formula | BSA = 0.007184 × height0.725 × weight0.425 |
How To Calculate BSA
To calculate body surface area, enter your height in centimeters and weight in kilograms. The calculator multiplies height by weight, divides the result by 3600, and then takes the square root.
Body Surface Area Guide
| BSA Range | General Meaning |
|---|---|
| Below 1.5 m² | Smaller body surface area |
| 1.5–2.0 m² | Common adult range |
| Above 2.0 m² | Larger body surface area |
BSA vs BMI
BMI compares weight with height to estimate weight category. BSA estimates total body surface area. Both use height and weight, but they answer different questions. BMI is often used for weight classification, while BSA is more common in medical calculations.
Why Doctors Use BSA
In clinical settings, BSA may be used for estimating certain medication dosing, cardiac index, kidney function indexing, and other medical calculations. However, this calculator should not be used to make treatment decisions.
Mosteller Formula Explained
The Mosteller formula is popular because it is simple and easy to calculate. It only needs height and weight. Although there are many BSA formulas, the Mosteller formula is widely used because it gives practical estimates for many people.
Limitations of This Calculator
BSA calculators provide estimates. They do not measure body composition, hydration, body fat, muscle mass, or health status. For medical use, always follow guidance from a healthcare professional.
Body Surface Area Calculator FAQ
What is a normal body surface area?
Many adults fall around 1.5 to 2.0 m², but normal values vary based on height, weight, age, and body size.
Is BSA the same as BMI?
No. BMI estimates weight category, while BSA estimates total body surface area.
Which BSA formula is used here?
This calculator mainly uses the Mosteller formula and also shows a Du Bois estimate for comparison.
Can I use this for medication dosing?
No. Do not use this calculator for medication decisions. Always follow medical advice from a qualified professional.