BSA Calculator
Calculate Body Surface Area (BSA) using multiple medical formulas including Du Bois, Mosteller, and Haycock. Free BSA calculator for accurate medical dosing and assessment.
Body Surface Area
1.85 m²
Reference Information
Average Adult
1.7 - 2.0 m²
Your BSA
| Formula | BSA |
|---|
BSA Formulas Comparison
| Formula | Equation | Notes |
|---|---|---|
| Du Bois & Du Bois (1916) | BSA = 0.007184 × H0.725 × W0.425 | Most widely used formula, considered the standard |
| Mosteller (1987) | BSA = √(H × W / 3600) | Simplest formula, easiest to calculate manually |
| Haycock (1978) | BSA = 0.024265 × H0.3964 × W0.5378 | Recommended for pediatric patients and children |
| Gehan & George (1970) | BSA = 0.0235 × H0.42246 × W0.51456 | Commonly used in cancer chemotherapy dosing |
| Boyd (1935) | BSA = 0.0003207 × H0.3 × W(0.7285 - 0.0188 log W) | Complex formula with logarithmic component |
| Fujimoto (1968) | BSA = 0.008883 × H0.663 × W0.444 | Developed specifically for Japanese populations |
| Takahira (1925) | BSA = 0.007241 × H0.725 × W0.425 | Early formula, similar to Du Bois |
Note: H = Height (cm), W = Weight (kg). All formulas calculate BSA in square meters (m²).
What is Body Surface Area (BSA)?
Body Surface Area (BSA) is the measured or calculated surface area of a human body. BSA is an important measurement in medicine, particularly for determining appropriate drug dosages, assessing metabolic mass, and calculating various physiological parameters.
Unlike body weight, BSA is a more accurate indicator of metabolic mass because surface area is less affected by abnormal adipose tissue. The average adult has a BSA of approximately 1.7 to 2.0 square meters (m²).
Clinical Uses of BSA
- Chemotherapy Dosing: Many cancer medications are dosed based on BSA to ensure appropriate therapeutic levels while minimizing toxicity
- Cardiac Index: Cardiac output is often normalized to BSA to calculate cardiac index (CI = CO/BSA)
- Renal Function: Glomerular filtration rate (GFR) is commonly indexed to BSA for standardized comparison
- Burn Assessment: The extent of burns is often calculated as a percentage of total BSA
- Medication Dosing: Various medications, especially in pediatrics, are dosed according to BSA
- Nutritional Assessment: Energy requirements and fluid needs can be estimated using BSA
- Clinical Research: BSA is used to normalize physiological measurements across different body sizes
Reference Values
- Average adult male: 1.9 m² (range: 1.7 - 2.0 m²)
- Average adult female: 1.6 m² (range: 1.5 - 1.8 m²)
- Newborn infant: approximately 0.25 m²
- 2-year-old child: approximately 0.5 m²
- 10-year-old child: approximately 1.14 m²
- 12-13 year old: approximately 1.33 m²
Important Notes
- Different formulas may give slightly different results - the Du Bois formula is most commonly used in clinical practice
- The Mosteller formula is gaining popularity due to its simplicity and ease of calculation
- For pediatric patients, the Haycock formula is often preferred
- BSA calculations assume normal body proportions and may be less accurate for individuals with extreme obesity or unusual body compositions
- Always consult with healthcare professionals for medication dosing decisions
- BSA is more reliable than body weight for drug dosing because it better correlates with many physiological functions
- The choice of formula may depend on the specific clinical application and population being studied