Pediatric Body Surface Area (BSA) Calculator

BSA (Wt.)

BSA

Pediatric Body Surface Area (BSA) estimation in children using weight alone (height is not required):

Weight (kg):

Weight must be between 1 and 90 kg.

Reference:
Sharkey, I., Boddy, A.V., Wallace, H., Mycroft, J., Hollis, R. and Picton, S., 2001. Body surface area estimation in children using weight alone: application in paediatric oncology. British journal of cancer, 85(1), pp.23-28.

Body Surface Area (BSA) calculated using various formulas:

Height (cm):

Height must be between 40 and 220

Weight (kg):

Weight must be between 1 and 150

Du Bois Formula: m²
Mosteller Formula: m²
Haycock Formula: m²
Gehan and George Formula: m²
Boyd Formula: m²
Fujimoto Formula: m²
Takahira Formula: m²

Mean BSA: m²

Body Mass Index (BMI):

Below are some of the most popular formulas for estimating BSA, where BSA is represented in m², W is weight in kg, and H is height in cm.

Du Bois formula:
BSA = 0.007184 × W^0.425 × H^0.725
^{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. Retrieved 2012-09-09.}

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

Haycock formula:
BSA = 0.024265 × W^0.5378 × H^0.3964
^{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 × W^0.51456 × H^0.42246
^{Gehan EA, George SL, Cancer Chemother Rep 1970, 54:225-235}

Boyd formula:
BSA = 0.03330 × W^{(0.6157 – 0.0188 × log₁₀(W)} × H^0.3
^{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 × W^0.444 × H^0.663
^{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 × W^0.425 × H^0.725
^{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.}

Body Surface Area (BSA) is a crucial parameter in pediatric clinical practice with several important use cases:

Dosage Calculation: BSA is commonly used to calculate medication dosages in pediatric patients. Since children vary significantly in size, BSA-based dosing provides a more accurate method for determining appropriate drug doses compared to weight-based dosing alone. This is particularly important for medications with narrow therapeutic indices or those that require precise dosing to achieve therapeutic efficacy while minimizing adverse effects.
Chemotherapy Dosing: In pediatric oncology, BSA plays a critical role in determining chemotherapy dosages. Chemotherapeutic agents are often administered based on BSA to ensure optimal drug exposure while minimizing the risk of toxicity. BSA-based dosing protocols are routinely used in pediatric cancer treatment to tailor chemotherapy regimens to individual patients’ body sizes and metabolic rates.
Fluid Resuscitation: BSA is used to calculate fluid resuscitation requirements in pediatric patients, especially in cases of burns, trauma, or severe dehydration. Fluid requirements are closely correlated with BSA, and using BSA-based calculations helps healthcare providers determine the appropriate volume and rate of fluid administration to maintain adequate hydration and prevent complications such as hypovolemic shock or electrolyte imbalances.
Nutritional Assessment: BSA is utilized in assessing nutritional requirements in pediatric patients, particularly those with significant growth impairment, malnutrition, or metabolic disorders. BSA-based calculations help healthcare providers determine appropriate caloric intake, macronutrient distribution, and micronutrient supplementation to support optimal growth and development in pediatric patients with nutritional needs.
Radiation Therapy Planning: In pediatric radiation oncology, BSA is used to determine radiation therapy dosages and treatment planning parameters. BSA-based calculations help radiation oncologists optimize treatment delivery while minimizing the risk of radiation-induced toxicity to normal tissues and organs. By adjusting radiation doses based on BSA, healthcare providers can tailor treatment plans to individual pediatric patients, maximizing therapeutic efficacy while minimizing long-term side effects.
Extracorporeal Membrane Oxygenation (ECMO): BSA is considered in the management of pediatric patients requiring ECMO support for severe respiratory or cardiac failure. BSA-based calculations help determine appropriate ECMO circuit size, blood flow rates, and oxygenation parameters, ensuring optimal support while minimizing the risk of complications such as circuit clotting or hemolysis.
Clinical Trials and Research: BSA is an essential parameter in pediatric clinical trials and research studies, particularly those involving drug development, pharmacokinetics, and pharmacodynamics. BSA-based dosing regimens allow researchers to standardize drug exposure across different age groups and body sizes, facilitating accurate efficacy and safety assessments in pediatric populations.

BMI (Body Mass Index) is an important clinical tool in pediatric practice with several key use cases:

Screening for Overweight and Obesity: BMI is used as a screening tool to identify children who may be overweight or obese. Pediatricians routinely calculate BMI during well-child visits to monitor growth patterns and assess weight status. Identifying excessive weight gain early allows for timely intervention and prevention of obesity-related health problems.
Assessment of Growth and Development: BMI provides a standardized measure of body composition relative to height, allowing healthcare providers to assess a child’s growth and development over time. Deviations from expected BMI percentiles may indicate growth disorders, nutritional deficiencies, or underlying medical conditions that require further evaluation and management.
Risk Assessment for Health Conditions: Elevated BMI in children is associated with an increased risk of various health conditions, including type 2 diabetes, hypertension, dyslipidemia, non-alcoholic fatty liver disease, orthopedic problems, and psychosocial issues. Pediatricians use BMI as a marker for assessing a child’s risk of developing these conditions and other obesity-related complications. Early identification of high-risk individuals allows for targeted interventions to mitigate health risks and improve long-term outcomes.
Guiding Interventions: BMI measurements guide healthcare providers in formulating appropriate interventions for overweight and obese children. These interventions may include lifestyle modifications (such as dietary changes and increased physical activity), behavioral counseling, and referral to specialized weight management programs or multidisciplinary care teams. Tailoring interventions based on BMI helps address individual needs and preferences, leading to more effective outcomes.
Monitoring Treatment Progress: For children undergoing weight management interventions or treatment for obesity-related health conditions, regular monitoring of BMI helps track progress and assess the effectiveness of interventions. Changes in BMI over time provide valuable feedback on the success of interventions and guide adjustments to treatment plans as needed to achieve desired outcomes.
Prevention Strategies: BMI data collected at the population level provides valuable insights into the prevalence of childhood obesity and helps inform public health initiatives aimed at prevention. By identifying high-risk groups and targeting interventions at the community level, public health efforts can promote healthy behaviors, improve access to nutritious foods, and create environments conducive to physical activity, thereby reducing the burden of childhood obesity and its associated health consequences.
Research and Epidemiology: BMI data from pediatric populations are utilized in research studies and epidemiological surveys to investigate trends in childhood obesity, identify risk factors, and evaluate the effectiveness of interventions. Research findings contribute to the development of evidence-based guidelines, policies, and programs aimed at addressing the complex factors influencing childhood obesity and promoting healthy weight management practices.