Body Surface Area Calculator
Calculate body surface area (BSA) using multiple proven formulas including Du Bois, Mosteller, Haycock, and Gehan & George.
Your Measurements
Enter your height and weight to calculate your Body Surface Area (BSA) using multiple proven formulas.
Average Body Surface Area
0.000 m²
Based on 4 formulas
Du Bois
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Mosteller
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Haycock
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Gehan & George
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BSA Formulas Comparison
BSA Range
BSA by Formula
| Formula | BSA (m²) | Notes |
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Complete User Guide
What is Body Surface Area (BSA)?
Body Surface Area (BSA) is the total surface area of the human body. It's measured in square meters (m²) and is used in various medical applications, particularly for calculating drug dosages, determining cardiac index, and assessing metabolic rate.
BSA provides a more accurate measure than body weight alone for many medical calculations, as it accounts for both height and weight, giving a better representation of body size.
BSA Calculation Formulas
Du Bois Formula (1916)
One of the oldest and most widely used formulas. Considered the gold standard.
BSA = 0.007184 × weight^0.425 × height^0.725
Where weight is in kg and height is in cm
Mosteller Formula (1987)
Simplified formula, easy to remember and calculate. Commonly used in clinical practice.
BSA = √((height × weight) / 3600)
Where height is in cm and weight is in kg
Haycock Formula (1978)
Developed specifically for pediatric populations but also accurate for adults.
BSA = 0.024265 × weight^0.5378 × height^0.3964
Where weight is in kg and height is in cm
Gehan & George Formula (1970)
Another commonly used formula, particularly in oncology and chemotherapy dosing.
BSA = 0.0235 × weight^0.51456 × height^0.42246
Where weight is in kg and height is in cm
Medical Applications of BSA
Drug Dosage Calculation: Many medications, especially chemotherapy drugs, are dosed based on BSA rather than body weight to ensure appropriate drug levels.
Cardiac Index: BSA is used to calculate cardiac index (cardiac output divided by BSA), which helps assess heart function.
Renal Function: Glomerular filtration rate (GFR) is often normalized to BSA for more accurate assessment of kidney function.
Metabolic Rate: BSA correlates with metabolic rate and is used in some metabolic calculations.
Fluid Requirements: Some fluid replacement calculations use BSA to determine appropriate volumes.
How to Use This Calculator
- Select your preferred unit system (Metric or Imperial)
- Enter your height accurately
- Enter your current weight
- Click 'Calculate BSA' to see your results
- Review the BSA values from all four formulas
- Compare the average BSA with individual formula results
- Use the charts to visualize differences between formulas
Understanding Your Results
Average BSA
The average of all four formulas provides a balanced estimate. This is often used when precision is important.
Individual Formula Results
Each formula may give slightly different results. The Du Bois formula is considered the gold standard, while Mosteller is the simplest to calculate.
Formula Differences
Small differences between formulas are normal and expected. The range chart shows the minimum, average, and maximum values.
Typical BSA Values
Adults: Typically ranges from 1.5 to 2.0 m² for average-sized adults
Children: BSA increases with age and size, ranging from approximately 0.2 m² for newborns to adult values
Men vs Women: Men typically have slightly higher BSA than women of the same height due to generally higher weight
Athletes: May have higher BSA due to increased muscle mass
Important Notes
- BSA calculations are estimates based on mathematical formulas. Actual body surface area may vary slightly.
- For medical purposes, always consult with healthcare professionals. BSA-based drug dosages should be calculated and verified by qualified medical personnel.
- Different formulas may be preferred for specific populations (e.g., pediatric vs adult, oncology vs general medicine).
- This calculator is for educational and informational purposes only. It should not replace professional medical advice or calculations.
Which Formula to Use?
Du Bois: Most accurate for general use, considered the gold standard. Recommended for most medical applications.
Mosteller: Simplest to calculate, commonly used in clinical practice. Good for quick estimates.
Haycock: Particularly accurate for pediatric populations. Also works well for adults.
Gehan & George: Often used in oncology and chemotherapy dosing calculations.
Average: Using the average of all formulas provides a balanced estimate and reduces the impact of outliers.