Body Surface Area Calculator | Best Calculator

Body Surface Area (BSA) Calculator

Male Female

Weight: Height:

Weight must be positive and greater than zero.

Height must be positive and greater than zero.

Please enter both weight and height. Weight and height must be positive and greater than zero.

BMI: 0.00 kg/m²

Formula	BSA (m²)	BSA (ft²)	BSA (in²)
Du Bois	0.00	0.00	0
Mosteller	0.00	0.00	0
Haycock	0.00	0.00	0
Gehan & George	0.00	0.00	0
Boyd	0.00	0.00	0
Fujimoto	0.00	0.00	0
Takahira	0.00	0.00	0
Schlich	0.00	0.00	0

Note: BSA values are calculated using various formulas. Results may vary slightly depending on the formula used.

Formula:
Using Du Bois: BSA = 0.007184 × W^0.425 × H^0.725
Example:
For W = 70 kg, H = 170 cm:
BSA = 0.007184 × 70^0.425 × 170^0.725 = 1.78 m²

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Table of average BSAs

	ft²	m²
Newborn child	2.69	0.25
Two-year-old child	5.38	0.5
Ten-year-old child	12.27	1.14
Adult female	17.22	1.6
Adult male	20.45	1.9

Understanding Body Surface Area (BSA)

What is Body Surface Area and Why is it Important?

Body Surface Area (BSA) is a key measurement used in healthcare, often preferred over just body weight because it gives a more accurate picture of a person’s metabolic mass. Metabolic mass refers to your body’s active tissues, like organs, bones, muscles, and blood, essentially everything except fat. Our BSA Calculator uses well-established formulas to estimate this value precisely for your needs.

How BSA is Used in Healthcare

BSA plays a vital role in several medical applications, including:

Chemotherapy Dosage

BSA is commonly used to calculate the right amount of chemotherapy drugs to administer. This helps ensure the treatment is effective while minimizing potential side effects. However, some experts argue against its use for drugs where even small dosage changes can have significant consequences (narrow therapeutic index). Despite these discussions, BSA generally remains a more consistent measure for drug dosing than relying solely on body weight.

Cardiac Index Assessment

BSA is crucial for determining the cardiac index, which compares how well your heart is pumping blood to the size of your body. This provides important information about your cardiovascular health.

Estimating Metabolic Mass

Since fat tissue isn’t actively involved in metabolism, BSA offers a more precise way to estimate a person’s metabolic mass. This is important for various medical procedures and assessments.

Formulas Used to Calculate BSA

Our calculator provides estimates based on these widely recognized formulas:

Du Bois Formula:

$BSA = 0.007184 \times W^{0.425} \times H^{0.725}$ This is the most frequently used formula and has been shown to be effective for individuals of varying weights. Reference: Du Bois D, Du Bois EF (Jun 1916). “A formula to estimate the approximate surface area if height and weight be known”. Archives of Internal Medicine 17 (6): 863-71. PMID 2520314.

Mosteller Formula:

$BSA = 0.016667 \times W^{0.5} \times H^{0.5}$ Reference: Mosteller RD. “Simplified calculation of body-surface area”. N Engl J Med 1987; 317:1098. PMID 3657876.

Haycock Formula:

$BSA = 0.024265 \times W^{0.5378} \times H^{0.3964}$ Reference: Haycock GB, Schwartz GJ, Wisotsky DH “Geometric method for measuring body surface area: A height-weight formula validated in infants, children and adults” J Pediatr 1978, 93:62-66.

Gehan and George Formula:

$BSA = 0.0235 \times W^{0.51456} \times H^{0.42246}$ Reference: Gehan EA, George SL, Cancer Chemother Rep 1970, 54:225-235

Boyd Formula:

$BSA = 0.03330 \times W^{(0.6157-0.0188 \times l o g 10 (W))} \times H^{0.3}$ Reference: Boyd, Edith (1935). The Growth of the Surface Area of the Human Body. University of Minnesota. The Institute of Child Welfare, Monograph Series, No. x. London: Oxford University Press

Fujimoto Formula:

$BSA = 0.008883 \times W^{0.444} \times H^{0.663}$ Reference: Fujimoto S, Watanabe T, Sakamoto A, Yukawa K, Morimoto K. Studies on the physical surface area of Japanese. 18. Calculation formulae in three stages over all ages. Nippon Eiseigaku Zasshi 1968;5:443-50.

Takahira Formula:

$BSA = 0.007241 \times W^{0.425} \times H^{0.725}$ Reference: Fujimoto S, Watanabe T, Sakamoto A, Yukawa K, Morimoto K. Studies on the physical surface area of Japanese. 18. Calculation formulae in three stages over all ages. Nippon Eiseigaku Zasshi 1968;5:443-50.

Schlich Formula:

For Women: $BSA = 0.000975482 \times W^{0.46} \times H^{1.08}$ For Men: $BSA = 0.000579479 \times W^{0.38} \times H^{1.24}$ Reference: Schlich E, Schumm M, Schlich M: “3-D-Body-Scan als anthropometrisches Verfahren zur Bestimmung der spezifischen Korperoberflache”. Ernahrungs Umschau 2010;57:178-183

Important Considerations and Limitations

While BSA is a valuable tool in clinical practice, it’s important to be aware of its limitations:

Accuracy at Extreme Sizes

BSA estimations may be less precise for individuals who are extremely tall or short, or have very high or very low body weights. In these situations, other measurements like BMI might offer a more reliable assessment.

Use with High-Risk Medications

When calculating dosages for medications with a narrow therapeutic index (where the safe and effective dose range is very small), extra caution is necessary. In such cases, BSA alone might not provide a sufficiently precise measurement for dosage calculation.