Body Surface Area Calculator
Calculate BSA using various medical formulas for dosing and assessment
Patient Measurements
Du Bois & Du Bois (1916) - Most widely used formula
BSA Calculation Results
Enter weight and height to calculate body surface area
Understanding Body Surface Area
What is Body Surface Area?
Body Surface Area (BSA) is the measured or calculated surface area of a human body. It's a crucial measurement in medicine because many physiological processes and drug dosages are more accurately correlated with BSA than with body weight alone.
Why BSA Matters:
- • More accurate drug dosing than weight alone
- • Correlates with cardiac output and renal function
- • Essential for chemotherapy dosing
- • Used in burn assessment and fluid management
BSA vs Body Weight
While body weight is commonly used for drug dosing, BSA often provides better accuracy, especially for medications with narrow therapeutic windows or significant toxicity profiles.
- •Weight-based dosing: Simple but less accurate for obese patients
- •BSA-based dosing: More accurate across different body types
- •Pediatric use: BSA is standard for children's medication dosing
- •Oncology: Essential for chemotherapy calculations
BSA Formula Comparison
| Formula | Year | Best For | Accuracy | Complexity |
|---|---|---|---|---|
| Du Bois & Du Bois | 1916 | Adults, general use | High | Medium |
| Mosteller | 1987 | Quick calculations | Good | Low |
| Haycock | 1978 | Children | Very Good | Medium |
| Boyd | 1935 | Research, high accuracy | Excellent | High |
Clinical Applications
Chemotherapy Dosing
Critical for cancer treatment
- • Most chemo drugs use BSA
- • Prevents under/overdosing
- • Reduces toxicity risk
- • Standard oncology practice
Cardiac Medications
Heart drug dosing
- • Antiarrhythmics
- • ACE inhibitors
- • Beta blockers
- • Digoxin dosing
Pediatric Dosing
Children's medications
- • Antibiotics
- • Antivirals
- • Pain medications
- • Anesthesia drugs
Burn Assessment
Burn treatment planning
- • Fluid resuscitation
- • Parkland formula
- • Nutritional needs
- • Graft requirements
Renal Function
Kidney assessment
- • GFR calculations
- • Creatinine clearance
- • Drug dosing adjustments
- • Dialysis planning
Nutritional Support
Metabolic calculations
- • Caloric needs
- • Protein requirements
- • TPN calculations
- • Wound healing
Reference Values
Average BSA by Age
BSA Categories
Small: < 1.4 m²
Children, small adults
Average: 1.4-1.8 m²
Typical adult range
Large: 1.8-2.2 m²
Tall or muscular adults
Very Large: > 2.2 m²
Very tall or obese patients
Safety Considerations
Important Notes
Medical Supervision Required: BSA calculations should always be performed by qualified healthcare professionals for clinical use.
Special Populations: Obese, elderly, and pediatric patients may require special considerations and alternative dosing methods.
Clinical Judgment: BSA is a tool, not a substitute for clinical judgment and individual patient assessment.
Formula Selection: Different formulas may give slightly different results; consistency in formula use is important for monitoring.
Related Calculators
Understanding Body Surface Area
BSA Definition
Body Surface Area (BSA) is the total surface area of the human body. This BSA calculator uses various medically-validated formulas to calculate BSA, which is essential for medical dosing and physiological assessments.
Medical Importance:
Critical for chemotherapy dosing, burn assessment, and cardiac output calculations.
BSA Applications
BSA provides a more accurate measure of body size for medical calculations than weight alone, especially for medication dosing and physiological assessments.
- •Medication Dosing: Chemotherapy and pediatric medications
- •Burn Assessment: Calculate total body surface area burned
- •Cardiac Index: Normalize cardiac output to body size
How to Use BSA Calculator
Step-by-Step Instructions
- 1.Enter Weight: Input your weight in kilograms or pounds for accurate calculation.
- 2.Enter Height: Input your height in centimeters or inches.
- 3.Select Formula: Choose from DuBois, Mosteller, Haycock, or Boyd formulas.
- 4.Calculate BSA: Click to get your body surface area in square meters.
BSA Calculation Formulas
DuBois Formula (Most Common)
BSA = 0.007184 × weight^0.425 × height^0.725
Weight in kg, Height in cm - Gold standard for medical calculations
Mosteller Formula
BSA = √(weight × height ÷ 60)
Simple and widely used
Haycock Formula
BSA = 0.024265 × weight^0.5378 × height^0.3964
Good for pediatric use
BSA Applications
Medical Applications
- • Chemotherapy dosing calculations
- • Pediatric medication dosing
- • Burn area assessment
- • Cardiac output normalization
Clinical Uses
- • Glomerular filtration rate estimation
- • Fluid replacement calculations
- • Nutritional assessments
- • Physiological parameter normalization
Frequently Asked Questions
Which BSA formula is most accurate?
The DuBois formula is considered the gold standard and most widely used in medical practice. However, Mosteller is preferred for its simplicity and similar accuracy.
Why is BSA used instead of weight for dosing?
BSA better correlates with physiological processes like metabolism and organ function than weight alone, making it more accurate for medication dosing.
Is BSA calculation different for children?
While the same formulas can be used, some formulas like Haycock are specifically validated for pediatric populations and may be preferred for children.
Understanding Your BSA Results
BSA Value
Your BSA in square meters represents your total body surface area, used for medical calculations and dosing.
Formula Differences
Different formulas may give slightly different results. Consistency in formula use is important for medical monitoring.
Medical Context
BSA is crucial for accurate medication dosing, especially in chemotherapy and pediatric medicine.
Conclusion
Body Surface Area calculation is essential for medical dosing and physiological assessments. Use the appropriate formula for your specific medical needs and always consult healthcare professionals for clinical applications.