Body Surface Area Calculator
Body Surface Area (BSA) is the measured or calculated surface area of the human body. It is widely used in medicine for drug dosing, cardiac output assessment, burn evaluation, and other clinical applications. BSA is often a better indicator than body weight for many physiological functions.
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About Body Surface Area
What is Body Surface Area?
Body Surface Area (BSA) is the measured or calculated surface area of the human body. It is widely used in medicine for drug dosing, cardiac output assessment, burn evaluation, and other clinical applications. BSA is often a better indicator than body weight for many physiological functions.
Calculation Formulas
- Du Bois: BSA (m²) = 0.007184 × Height(cm)^0.725 × Weight(kg)^0.425
- Mosteller: BSA (m²) = √(Height(cm) × Weight(kg) / 3600)
- Haycock: BSA (m²) = 0.024265 × Height(cm)^0.3964 × Weight(kg)^0.5378
- Gehan & George: BSA (m²) = 0.0235 × Height(cm)^0.42246 × Weight(kg)^0.51456
- Boyd: BSA (m²) = 0.0003207 × Height(cm)^0.3 × Weight(g)^(0.7285 - 0.0188 × log(Weight(g)))
- Fujimoto: BSA (m²) = 0.008883 × Height(cm)^0.663 × Weight(kg)^0.444
- Takahira: BSA (m²) = 0.007241 × Height(cm)^0.725 × Weight(kg)^0.425
- Schlich: Males: 0.000579479 × Height(cm)^1.24 × Weight(kg)^0.38; Females: 0.000975482 × Height(cm)^1.08 × Weight(kg)^0.46
Clinical Uses of BSA
- Drug dosage calculation, especially for chemotherapy and other critical medications
- Cardiac function assessment (cardiac index = cardiac output / BSA)
- Burn area assessment and fluid replacement therapy
- Basal metabolic rate calculations
- Fluid requirements and renal clearance calculations
Accuracy of BSA Calculations
Different formulas may be more accurate for specific populations. For pediatric patients, the Haycock or Mosteller formulas are often preferred. For Asian populations, the Fujimoto formula may provide better results. The average of multiple formulas is commonly used in clinical practice.
Medical Disclaimer
This calculator is for informational purposes only and is not a substitute for professional medical advice. Always consult with a healthcare provider for medical decisions, especially regarding medication dosing.
What is Body Surface Area?
Body Surface Area (BSA) is the measured or calculated surface area of the human body. It is widely used in medicine for drug dosing, cardiac output assessment, burn evaluation, and other clinical applications. BSA is often a better indicator than body weight for many physiological functions.
BSA is widely used in medicine because many physiological processes correlate more closely with surface area than with weight. For example, basal metabolic rate, cardiac output, and renal function all correlate better with BSA than with body weight.
Calculation Formulas
Du Bois & Du Bois (1916)
The original and most widely used formula. Developed in 1916 based on measurements of only 9 individuals, but still considered reliable for most adults.
$$BSA (m²) = 0.007184 × Height(cm)^{0.725} × Weight(kg)^{0.425}$$
Mosteller (1987)
A simplified formula that is easy to calculate and remember. It provides good accuracy across different age groups and body types.
$$BSA (m²) = \sqrt{\frac{Height(cm) × Weight(kg)}{3600}}$$
Haycock (1978)
Validated in infants, children, and adults. Often considered more accurate for pediatric patients than the Du Bois formula.
$$BSA (m²) = 0.024265 × Height(cm)^{0.3964} × Weight(kg)^{0.5378}$$
Clinical Uses of BSA
info.usesDrugDosage
For drug dosing, the appropriate BSA formula may depend on the specific medication and patient population.
info.usesCardiacFunction
In pediatric patients, the Haycock or Mosteller formulas are often preferred.
info.usesBurnAssessment
For obese patients, BSA-based dosing may lead to overdosing of some medications.
info.usesMetabolicRate
When high precision is required, consider using multiple formulas and consulting with a healthcare professional.
Normal BSA Reference Values
The following are approximate BSA ranges for different age groups. Individual values may vary based on body composition and other factors.
| Category | BSA Range (m²) |
|---|---|
| Newborn | 0.25 - 0.38 |
| Infant (6 months) | 0.40 - 0.45 |
| Infant (12 months) | 0.47 - 0.52 |
| Adult Female | 1.50 - 1.80 |
| Adult Male | 1.70 - 2.00 |
常见问题
为什么BSA用于药物剂量计算？
体表面积与多种生理功能相关，包括血容量、心输出量和肾功能等。研究表明，药物剂量与BSA的相关性比与体重的相关性更好，尤其是化疗药物。
哪种BSA计算公式最准确？
没有一种公式对所有人群都最准确。Mosteller公式因其简单性和相对准确性而被广泛使用；Haycock公式对儿童可能更准确；而较新的Schlich公式考虑了性别差异。
BSA计算有什么局限性？
BSA计算公式基于统计数据，可能不适用于极端体型的人群，如极度肥胖或极瘦的人。此外，不同公式可能会产生略有不同的结果，这在临床药物剂量计算中需要考虑。