BSA Calculator | Calculate Body Surface Area

Body Surface Area (BSA) is an important measurement in medicine used to calculate medication dosages, assess organ function, and estimate physiological parameters. Unlike weight or height alone, BSA provides a more accurate representation of a person’s body size. A BSA Calculator helps you quickly determine this value without manual errors.

Why BSA Is Important

• Medical Dosage: Many chemotherapy and drug doses are calculated based on BSA.
• Physiological Assessment: Used in cardiology, nephrology, and pediatrics for body function evaluation.
• Research: Essential in clinical trials and medical research.
• Health Monitoring: Helps track growth and body size in children and adults.

Common Formulas to Calculate BSA

BSA is calculated using several formulas. The most widely used are:

• Mosteller Formula: BSA (m²) = √((Height(cm) × Weight(kg)) / 3600)
• Du Bois Formula: BSA (m²) = 0.007184 × Weight(kg)^0.425 × Height(cm)^0.725
• Haycock Formula: BSA (m²) = 0.024265 × Weight(kg)^0.5378 × Height(cm)^0.3964

How the BSA Calculator Works

1. Enter your weight (kg) and height (cm).
2. Select the formula you want to use (Mosteller, Du Bois, Haycock).
3. The calculator automatically computes the BSA in square meters (m²).
4. Use the result to adjust medication doses or assess physiological parameters.

Step-by-Step Example 1: Using Mosteller Formula

Problem: Calculate the BSA of a person weighing 70 kg and height 175 cm.
Formula: BSA = √((Height × Weight) / 3600)
Calculation: BSA = √((175 × 70) / 3600) = √(12250 / 3600) = √3.4028 ≈ 1.84 m²

Step-by-Step Example 2: Using Du Bois Formula

Problem: Calculate BSA for the same person.
Formula: BSA = 0.007184 × Weight^0.425 × Height^0.725
Calculation: BSA = 0.007184 × 70^0.425 × 175^0.725 ≈ 1.84 m²

Step-by-Step Example 3: Using Haycock Formula

Problem: Calculate BSA for 70 kg, 175 cm.
Formula: BSA = 0.024265 × Weight^0.5378 × Height^0.3964
Calculation: BSA = 0.024265 × 70^0.5378 × 175^0.3964 ≈ 1.85 m²

FAQs – BSA Calculator

1. What is BSA?
BSA stands for Body Surface Area, representing the total surface area of the human body in square meters.

2. Why is BSA important for medications?
Some drugs, especially chemotherapy agents, are dosed based on BSA to ensure effectiveness and reduce toxicity.

3. Which formula is most accurate?
Mosteller formula is widely used for its simplicity and accuracy. Du Bois and Haycock are also reliable for clinical use.

4. Can children use this calculator?
Yes, BSA calculation applies to all ages; formulas adjust for smaller body sizes.

5. Do I need height in cm or inches?
Most formulas use cm for height and kg for weight.

6. Can I calculate BSA without a calculator?
Yes, formulas can be calculated manually, but an online BSA calculator is faster and reduces errors.

7. Is BSA used in cardiology?
Yes, it helps normalize cardiac output, blood flow, and other physiological measurements.

8. Can BSA change over time?
Yes, as weight or height changes, BSA changes accordingly.

9. Is BSA the same as BMI?
No, BMI measures body mass relative to height; BSA measures total body surface area.

10. Is this calculator free and easy to use?
Yes, it’s free, fast, and works on any modern browser.