Body Surface Area (BSA) Calculator
Calculate body surface area in square meters (m²) using Mosteller, Du Bois, and Haycock formulas for clinical medication and cardiac indexing.
What is Body Surface Area (BSA)?
Body Surface Area (BSA) is the measured or calculated surface area of a human body expressed in square meters ($m^2$). In clinical medicine, pharmacology, and physiology, BSA is considered a superior biometric index compared to body weight alone because it correlates directly with metabolic rate, cardiac output, renal blood flow, and physiological heat exchange.
For deeper analysis and related planning, you can also explore our BMI Calculator and BMR Calculator.
Primary Clinical BSA Formulas
Clinical Applications of BSA
- Chemotherapy and Oncology Dosing: Narrow therapeutic window chemotherapeutics (such as cisplatin, 5-FU, and doxorubicin) are prescribed in milligrams per square meter of BSA ($mg/m^2$) to avoid organ toxicity.
- Renal Clearance Indexing (eGFR): Glomerular filtration rates are standardized to an average adult BSA of $1.73 \text{ m}^2$ (expressed as $mL/min/1.73 m^2$).
- Cardiac Index: Cardiac output normalized to patient size: $\text{Cardiac Index} = \text{Cardiac Output} / \text{BSA}$. Normal adult resting cardiac index is $2.5 \text{ to } 4.0 \text{ L/min/m}^2$.
Medical YMYL Disclaimer: This calculator provides mathematical estimations for educational and academic reference only. Medication doses and medical treatment regimens must strictly be verified by licensed medical professionals and clinical pharmacists using hospital protocols.
Frequently Asked Questions
What is normal Body Surface Area (BSA) for an adult?
The average BSA for an adult male is approximately 1.9 m², and for an adult female is approximately 1.6 m². A value of 1.73 m² is widely used as the universal standard reference benchmark for normalizing clinical physiological values.
Why is BSA used instead of body weight for medical dosages?
BSA correlates more accurately with metabolic rate, cardiac output, renal glomerular filtration rate, and blood volume than body weight alone, because adipose tissue has lower metabolic activity than lean muscle mass.
What is the Mosteller formula for BSA?
The Mosteller formula is: BSA (m²) = √[ (Height in cm × Weight in kg) / 3600 ]. For imperial units, BSA (m²) = √[ (Height in inches × Weight in lbs) / 3131 ].