Body Surface Area (BSA) Calculator
Calculate body surface area using the Mosteller formula, commonly used in medicine for drug dosing calculations, burn assessment, and cardiac index determination. This tool is for educational reference only.
👨⚕️ Clinical Reference📐 BSA = √(Height(cm) × Weight(kg) / 3600)🏥 Health
Height (cm)
Weight (kg)
Please enter valid values.
Formula & Reference
| Variable | Symbol | Formula | Units |
|---|---|---|---|
| Body Surface Area (BSA) Calculator | — | BSA = √(Height(cm) × Weight(kg) / 3600) | m² |
Step-by-Step Examples
Example 1
Average Adult
Height 175cm, weight 70kg.
- BSA = √((175×70)/3600) = √(12250/3600) = √3.40
- BSA = 1.85 m²
- Close to average adult BSA (~1.7-2.0 m²)
✓ BSA ≈ 1.85 m²
Example 2
Smaller Adult
Height 160cm, weight 55kg.
- BSA = √((160×55)/3600) = √(8800/3600) = √2.44
- BSA = 1.56 m²
✓ BSA ≈ 1.56 m²
Example 3
Larger Adult
Height 190cm, weight 95kg.
- BSA = √((190×95)/3600) = √(18050/3600) = √5.01
- BSA = 2.24 m²
✓ BSA ≈ 2.24 m²
Real-World Applications
Pharmacology Education
BSA is used in clinical settings to calculate certain medication doses (especially chemotherapy), though actual prescribing should always involve a healthcare provider.
Cardiac Index Reference
BSA normalizes cardiac output (CO/BSA = cardiac index) for comparing heart function across different body sizes.
Burn Assessment Education
Burn severity percentage calculations in medical training reference total body surface area.
Medical Education
BSA calculations are a standard topic in nursing, pharmacy, and medical school coursework.
Common Mistakes to Avoid
⚠️
Using BSA for personal medication dosing
This calculator is for educational reference only. Medication dosing must always be determined by a licensed healthcare provider based on complete clinical context.
⚠️
Confusing different BSA formulas
Mosteller, Du Bois, and Haycock formulas give slightly different results. Clinical settings typically specify which formula to use for consistency.
⚠️
Assuming BSA scales linearly with weight
BSA increases roughly with weight^0.5, not 1:1 — doubling weight does not double BSA, a common misconception.
Frequently Asked Questions
What is BSA used for in medicine? ▾
Body Surface Area is used clinically for certain medication dosing (particularly chemotherapy), burn injury assessment, and normalizing cardiac measurements across different body sizes.
What is the Mosteller formula? ▾
BSA = √(Height(cm) × Weight(kg) / 3600). It's one of several validated formulas, chosen here for its simplicity and reasonable accuracy across most body types.
What is a normal BSA range? ▾
Average adult BSA is approximately 1.7-2.0 m², though this varies significantly with height and weight. Smaller individuals may have BSA around 1.4-1.5 m², larger individuals 2.2+ m².
Is this calculator a substitute for medical advice? ▾
No. This tool provides general educational information only. Any medical dosing or clinical decisions must be made by a qualified healthcare professional with full patient context.
What is cardiac index? ▾
Cardiac Index = Cardiac Output / BSA. This normalization allows meaningful comparison of heart function across patients of different body sizes in clinical cardiology.