Body Surface Area Calculator

Body Surface Area Calculator

Calculate body surface area using multiple formulas

About Body Surface Area Calculator

Our comprehensive body surface area calculator helps healthcare professionals, researchers, and individuals determine the total surface area of the human body using multiple validated formulas. This essential medical tool provides accurate BSA calculations to support drug dosing, medical procedures, burn assessment, and various clinical applications.

What It Calculates

  • Body Surface Area: Total external surface area in square meters
  • Multiple Formulas: Various calculation methods for accuracy
  • Formula Comparison: Side-by-side analysis of different approaches
  • Personalized Results: Based on age, gender, height, and weight
  • Clinical Applications: Medical dosing and procedure planning
  • Research Support: Scientific and medical research applications

Calculation Formulas Explained

DuBois & DuBois (1916)
  • Most widely used formula
  • BSA = 0.007184 × W^0.425 × H^0.725
  • Validated in multiple studies
  • Good for most populations
  • Standard in clinical practice
  • Weight in kg, height in cm
Mosteller (1987)
  • Simplified calculation
  • BSA = √(W × H) / 60
  • Easy to remember
  • Good accuracy
  • Weight in kg, height in cm
  • Widely used in pediatrics

Specialized Formulas

Haycock (1978)
  • Developed for children
  • More accurate for pediatric use
  • Accounts for growth patterns
  • Used in pediatric oncology
  • Validated in young populations
  • BSA = 0.024265 × W^0.5378 × H^0.3964
Gehan & George (1970)
  • Based on body density
  • Accounts for body composition
  • Good for varied populations
  • Used in research settings
  • More complex calculation
  • Includes age and gender
Boyd (1935)
  • Early comprehensive formula
  • Includes age and gender
  • Good for adults
  • Used in some clinical settings
  • More complex than DuBois
  • Historical significance

Understanding Your Results

Body Surface Area

Total surface area in m²

Formula Comparison

All methods side-by-side

Recommendations

Personalized guidance

How to Use

Enter your age, gender, weight, and height. Choose your preferred calculation formula, and the calculator will provide your body surface area along with comparisons of all available formulas to help you understand the range of possible values.

Clinical Applications

Drug Dosing:

  • Chemotherapy medications
  • Antibiotics and antivirals
  • Cardiovascular drugs
  • Pediatric medications
  • Oncology treatments
  • Critical care medications

Medical Procedures:

  • Burn assessment and treatment
  • Fluid resuscitation
  • Dialysis prescriptions
  • Ventilator settings
  • Nutritional requirements
  • Radiation therapy planning

BSA vs. Body Weight Dosing

  • BSA Dosing: More accurate for many medications
  • Weight Dosing: Simpler but less precise
  • Metabolic Rate: BSA better correlates with metabolism
  • Drug Distribution: BSA reflects tissue distribution
  • Pediatric Use: BSA essential for children
  • Oncology Standard: BSA required for chemotherapy

Factors Affecting BSA

  • Body Size: Larger individuals have greater BSA
  • Body Shape: Taller people have more surface area
  • Age: BSA changes with growth and aging
  • Gender: Different body compositions affect BSA
  • Body Composition: Muscle vs. fat distribution
  • Pregnancy: Increases BSA during gestation

BSA in Different Populations

Adults
  • Typical range: 1.4-2.2 m²
  • DuBois formula most accurate
  • Used for most medications
  • Standard clinical practice
  • Good formula agreement
  • Stable over time
Children
  • Range: 0.2-1.8 m²
  • Haycock formula recommended
  • Rapid changes with growth
  • Critical for drug dosing
  • Age-specific considerations
  • Pediatric oncology standard

Burn Assessment

  • Rule of Nines: Body part percentages for burns
  • Lund-Browder Chart: Age-adjusted burn assessment
  • BSA Calculation: Essential for burn severity
  • Fluid Resuscitation: Based on BSA and burn percentage
  • Prognosis: BSA affects survival rates
  • Treatment Planning: BSA guides therapy decisions

Research Applications

  • Clinical Trials: Standardized dosing protocols
  • Epidemiology: Population health studies
  • Physiology Research: Metabolic rate studies
  • Drug Development: Pharmacokinetic modeling
  • Medical Device Design: Equipment sizing
  • Public Health: Population assessments

Limitations and Considerations

  • Formula Variation: Different methods give different results
  • Population Specificity: Some formulas better for certain groups
  • Body Shape Assumptions: Formulas assume standard proportions
  • Extreme Cases: Very tall/short or obese individuals
  • Amputations: BSA calculations may need adjustment
  • Clinical Judgment: Always consider individual factors

When to Use Each Formula

  • DuBois & DuBois: General adult population, clinical practice
  • Mosteller: Quick estimates, pediatrics, research
  • Haycock: Children, pediatric oncology, growth studies
  • Gehan & George: Research, varied populations
  • Boyd: Historical reference, some clinical settings
  • Multiple Formulas: Compare results for accuracy
Pro Tip

For most clinical applications, the DuBois & DuBois formula provides the most reliable results. However, always consider your specific use case - use Haycock for children, Mosteller for quick estimates, and compare multiple formulas when accuracy is critical. Remember that BSA is just one factor in medical decision-making; always consult with healthcare professionals for clinical applications. Also, be aware that BSA calculations are estimates and may need adjustment for individuals with unusual body proportions or specific medical conditions.