Body Surface Area Calculator

Body Surface Area (BSA) Calculator helps medical professionals and patients calculate BSA using the Du Bois formula. BSA is critical for determining chemotherapy dosages, medication calculations, cardiac index, and burn severity assessment.

BSA represents the total surface area of the human body in square meters. Unlike BMI which only uses height and weight separately, BSA considers both together to assess body size more accurately for medical purposes.

Key Features:
- Calculate BSA using Du Bois formula
- Alternative formulas (Mosteller, Haycock, Gehan-George)
- Support for pediatric and adult calculations
- Metric and imperial unit support
- Medical dosage calculation assistance
- Instant accurate results
- Works offline in clinical settings
- Share BSA with healthcare providers
- No registration or login required
- Remove ads for professional use

Perfect For:
- Chemotherapy dosage calculation
- Medication dosing (especially oncology)
- Cardiac output assessment (cardiac index)
- Burn severity estimation (Rule of Nines)
- Renal function normalization (GFR)
- Fluid resuscitation calculations
- Clinical research and trials
- Medical education and training

BSA Formulas:

Du Bois Formula (Most Common):
BSA (m²) = 0.007184 × height(cm)^0.725 × weight(kg)^0.425

Mosteller Formula (Simple):
BSA (m²) = √[(height(cm) × weight(kg)) / 3600]

Haycock Formula:
BSA (m²) = 0.024265 × height(cm)^0.3964 × weight(kg)^0.5378

Gehan-George Formula:
BSA (m²) = 0.0235 × height(cm)^0.42246 × weight(kg)^0.51456

Example:
Adult male: 175 cm, 75 kg
BSA (Du Bois) = 0.007184 × 175^0.725 × 75^0.425
BSA = 1.91 m²

BSA Reference Ranges:
- Average adult male: 1.9 m²
- Average adult female: 1.6 m²
- Children (10 years): ~1.1 m²
- Infants (1 year): ~0.5 m²
- Neonates: ~0.25 m²

Clinical Applications:

Chemotherapy Dosing:
Many chemo drugs dosed per BSA (mg/m²)
Example: Doxorubicin 60 mg/m²
Patient BSA: 1.8 m²
Dose: 60 × 1.8 = 108 mg

Cardiac Index:
Cardiac Index = Cardiac Output / BSA
Normal: 2.5-4.0 L/min/m²
Helps assess heart function independent of body size

Glomerular Filtration Rate (GFR):
eGFR normalized to 1.73 m² BSA for comparison
Adjusts kidney function for body size

Burn Assessment:
Wallace Rule of Nines uses BSA percentages
Adult: Head 9%, Each arm 9%, Torso front/back 18% each, Each leg 18%
Determines fluid resuscitation needs

Fluid Requirements:
Maintenance fluids often calculated per BSA
1,500-2,000 ml/m²/day for adults
Accounts for metabolic rate differences

Important Notes:
- BSA alone doesn't indicate health (like BMI limitations)
- Extreme obesity or cachexia affects formula accuracy
- Pediatric calculations need age-appropriate formulas
- Always verify calculations before medication administration
- Chemotherapy dosing may cap at BSA 2.0-2.2 m² (obesity)

Medical Safety:
BSA calculations are critical for patient safety. Double-check all calculations, especially for high-risk medications like chemotherapy. When in doubt, consult pharmacy or use clinical decision support tools.

Research Applications:
Clinical trials often normalize data by BSA to compare patients of different sizes. Metabolic rate, heat loss, and many physiological parameters correlate better with BSA than with weight alone.

Download BSA Calculator for accurate medical calculations!