Body Surface Area Calculator
Calculate BSA using multiple scientific formulas for medical applications
Body Surface Area Calculator
Calculate BSA using multiple scientific formulas for medical and health applications
Select BSA Formula:
Height
Examples: 170 cm, 5'7&qout; (enter 5.58 in feet), 67 inches
Weight
Examples: 70 kg, 154 lbs
Medical Applications of BSA
🏥 Clinical Uses
Chemotherapy Dosing
Most cancer drugs are dosed per m² of BSA to optimize efficacy and minimize toxicity
Renal Function Assessment
Glomerular filtration rate (GFR) is normalized to 1.73 m² for comparison across patients
Cardiac Measurements
Cardiac output and index are expressed per m² to account for body size
Burn Assessment
Total body surface area burned guides fluid resuscitation and treatment
📊 Formula Comparison Guide
| Formula | Year | Best For | Accuracy |
|---|---|---|---|
| Mosteller | 1987 | General use | ⭐⭐⭐⭐⭐ |
| Du Bois | 1916 | Historical standard | ⭐⭐⭐⭐ |
| Haycock | 1978 | Pediatrics | ⭐⭐⭐⭐⭐ |
| Gehan & George | 1970 | Research | ⭐⭐⭐⭐ |
| Boyd | 1935 | Extreme sizes | ⭐⭐⭐⭐ |
💡 Medical Note: Always consult healthcare professionals for medical dosing. These calculations are for educational purposes.
📈 Average BSA Values by Age and Gender
| Age Group | Male Average (m²) | Female Average (m²) | Typical Range (m²) |
|---|---|---|---|
| Newborn | 0.25 | 0.24 | 0.20-0.30 |
| 2 years | 0.56 | 0.54 | 0.50-0.62 |
| 10 years | 1.14 | 1.10 | 1.00-1.28 |
| Adult (20-40) | 1.90 | 1.60 | 1.50-2.20 |
| Elderly (70+) | 1.82 | 1.55 | 1.40-2.00 |
Factors Affecting BSA:
- Height: Primary determinant of BSA
- Weight: Secondary factor in calculations
- Body Composition: Muscle vs. fat distribution
- Age: Children have higher BSA/weight ratio
- Gender: Typically higher in males at same height
Interesting Facts:
- BSA of average adult is about 1.7-2.0 m²
- Skin is the body's largest organ by surface area
- BSA correlates better with metabolic rate than weight alone
- Used in dermatology for psoriasis treatment dosing
Frequently Asked Questions
BSA is the total surface area of the human body. It's used in medical practice to calculate drug dosages, determine physiological measurements, and assess metabolic mass.
Many medical treatments, especially chemotherapy drugs, are dosed based on BSA rather than weight alone. It provides a more accurate measure of metabolic mass and helps standardize drug administration across different body sizes.
The Mosteller formula is most commonly used due to its simplicity and reasonable accuracy. The Du Bois formula was the original standard. The Haycock formula is often preferred for pediatric populations.
BMI measures body mass relative to height squared, while BSA estimates total external surface area. BMI is used for obesity classification, while BSA is used for medical dosing and physiological measurements.
While BSA is primarily medical, it can provide insight into metabolic rate estimation. Larger surface areas typically correlate with higher basal metabolic rates due to greater heat loss.
BSA should be recalculated when there's significant weight change (>5-10% body weight) or when starting new medical treatments. For general monitoring, recalculating every 3-6 months is reasonable.
👨⚕️ For Medical Professionals
98%
Of chemotherapy drugs use BSA dosing
±5%
Typical variation between formulas
1.73
Standard BSA for renal function (m²)
Sources: American Society of Clinical Oncology, Journal of Clinical Oncology
