Body Surface Area Calculator
Calculate your Body Surface Area (BSA) using multiple medical formulas. BSA is used for drug dosing, cardiac calculations, and metabolic assessments.
Formula:BSA = √(Height × Weight / 3600)
Body Surface Area
BSA
1.948 m²
Dubois formula
Average (All Formulas)1.956 m²
Comparison to Standard112.6% of 1.73 m²
Body Surface Area
BSA
1.948 m²
Dubois formula
Average (All Formulas)1.956 m²
Comparison to Standard112.6% of 1.73 m²
Formula Selection
Measurements
Formula Comparison
| Formula | Description | BSA (m²) |
|---|---|---|
| DuBois | Most widely used (1916) | 1.9480 |
| Mosteller | Simple & accurate (1987) | 1.9515 |
| Haycock | Good for children (1978) | 1.9577 |
| Gehan | Gehan & George (1970) | 1.9616 |
| Boyd | Boyd formula (1935) | 1.9603 |
Average BSA: 1.956 m²Range: 1.948 - 1.962 m²
BSA Formulas
DuBois & DuBois (1916):
BSA = 0.007184 × W^0.425 × H^0.725
Mosteller (1987):
BSA = sqrt((H × W) / 3600)
Haycock (1978):
BSA = 0.024265 × W^0.5378 × H^0.3964
W = weight in kg, H = height in cm
BSA Reference Values
| Category | BSA Range (m²) |
|---|---|
| Newborn | 0.2 - 0.25 |
| Child (2 years) | 0.5 - 0.55 |
| Child (9 years) | 1.0 - 1.1 |
| Adult Female (average) | 1.6 - 1.8 |
| Adult Male (average) | 1.7 - 2.0 |
Standard reference BSA: 1.73 m² (used in medical calculations)
Medical Applications of BSA
Drug Dosing
Chemotherapy drugs are often dosed in mg/m² for more accurate dosing across different body sizes.
Cardiac Index
Cardiac output divided by BSA gives cardiac index, allowing comparison between individuals.
GFR Standardization
Glomerular filtration rate is often standardized to 1.73 m² BSA for comparison.
Burn Assessment
Burn area is calculated as percentage of total BSA to determine treatment.
BSA Scenarios
Explore how changes affect your results
Your BSA vs Population
Compared to the general population
Your BSA
1.948 m²
Percentile
69th
There's room for improvement
Distribution
You
Small
1.500
Below Avg
1.650
Average
1.800
Above Avg
2.000
Large
2.200
Your Ranking
Top 69%
31% are higher
BSA Information
Based on your results
0/4 completed
⚕️ MedicalRecommended
Your BSA Value
Your body surface area is 1.948 m², which is 113% of the standard 1.73 m² reference value.
⚕️ MedicalRecommended
Drug Dosing Implications
BSA-based drug dosing helps ensure accurate medication amounts for your body size.
⚕️ MedicalOptional
Formula Selection
The DuBois and Mosteller formulas are most commonly used for adults.
Frequently Asked Questions
Body Surface Area (BSA) is the measured or calculated surface area of a human body, expressed in square meters (m²). It's used in medicine for drug dosing (especially chemotherapy), determining cardiac index, and calculating metabolic rates.
BSA correlates better with metabolic mass than body weight alone. Many drugs, especially chemotherapy agents, are dosed per m² of BSA for more accurate dosing across different body sizes. It's also used to calculate cardiac output and renal function.
Average adult BSA is approximately 1.7-2.0 m² for men and 1.6-1.8 m² for women. A "standard" adult BSA of 1.73 m² is often used as a reference value. Children have proportionally larger BSA relative to weight.
DuBois is the most widely used and accepted. Mosteller is simpler and equally accurate for most adults. Haycock is preferred for pediatric patients. The choice often depends on institutional preference and patient population.
BSA and BMI are different measures. BMI uses weight/height² and indicates weight status. BSA estimates actual skin surface area. A tall, lean person and a short, heavy person might have similar BSA but very different BMIs.
How this works
Formulas are implementations of published clinical or public-health equations. Calculations run in your browser — no inputs are transmitted to our servers and no account is required. The result is informational; it does not diagnose, treat, or replace advice from a clinician.
What this tool can’t do
When to consult a professional
Talk to a licensed healthcare provider before using the output of this tool to make a medical decision, especially if you have an underlying condition, are pregnant, or are on medication that affects metabolism or fluid balance.
Sources
- [1]Centers for Disease Control and Prevention (CDC)Official sourcecdc.govAccessed Apr 21, 2026
- [2]National Institutes of Health (NIH)Official sourcenih.govAccessed Apr 21, 2026
Joseph OrdunaFounder & Software Engineer
Full-stack software engineer specializing in embedded systems, web architecture, and AI/ML. Founder of Practical Web Tools. Built the gesture-controlled drone IP acquired by KD Interactive (Aura Drone, sold on Amazon).
Body Surface Area
BSA
1.948 m²
Dubois formula
Average (All Formulas)1.956 m²
Comparison to Standard112.6% of 1.73 m²