Body Surface Area Calculator
Clinical Body Surface Area (BSA) calculator for medical dosing, chemotherapy indexing, and physiological monitoring. Compare results across 8 validated formulas in metric and imperial units.
Body Surface Area (BSA) Calculator
Calculate your total body surface area in m² using standard medical formulas.
Body Surface Area (BSA): Mosteller Formula, Pharmacokinetics & Clinical Dosing
Body Surface Area (BSA) measures the total external surface area of the human body in square meters (m²), serving as a crucial parameter in clinical pharmacokinetics and metabolic rate indexing.
Clinical Applications: Chemotherapy and Renal Clearance
BSA provides a more accurate metric of metabolic mass and drug distribution volume than total body weight alone. It is universally applied for dosing narrow-therapeutic-index medications like chemotherapeutic agents.
The Mosteller formula—BSA (m²) = sqrt((Height(cm) x Weight(kg)) / 3600)—is the international standard owing to its accuracy and mathematical simplicity.
Step-by-Step Instructions
Select Measurement System
Choose Metric units (kilograms and centimeters) or Imperial units (pounds and inches).
Enter Current Height & Weight
Input exact standing height and current body weight.
Compare Clinical BSA Formulas
Review Body Surface Area calculations across Mosteller, Du Bois, Haycock, Gehan-George, and Boyd formulas.
Review Medical Applications
Evaluate BSA output ($m^2$) utilized for chemotherapy dosing, cardiac index normalization, and renal clearance.
Key Features & Capabilities
- Mosteller Formula: $\text{BSA } (m^2) = \sqrt{\frac{\text{Height (cm)} \times \text{Weight (kg)}}{3600}}$
- Du Bois & Du Bois clinical standard: $\text{BSA } (m^2) = 0.007184 \times \text{Weight (kg)}^{0.425} \times \text{Height (cm)}^{0.725}$
- Haycock pediatric equation and Gehan-George oncology standard comparisons
- Cardiac Index normalization (Cardiac Output / BSA) and Burn Lund-Browder TBSA calculation
Frequently Asked Questions
What is Body Surface Area (BSA) and why is it used in medicine?
Body Surface Area (BSA) is the measured or calculated total surface area of the human body, expressed in square meters (m²). In clinical medicine, BSA is a superior physiological indicator of metabolic mass and cardiac output than body weight alone because it is less affected by abnormal adipose tissue mass, making it standard for chemotherapy dosing and dialysis clearance.
What is the Mosteller formula for calculating BSA?
Published by Dr. Robert Mosteller in 1987 in the *New England Journal of Medicine*, the formula is: $\text{BSA } (m^2) = \sqrt{\frac{\text{Height (cm)} \times \text{Weight (kg)}}{3600}}$ (or $\sqrt{\frac{\text{Height (in)} \times \text{Weight (lbs)}}{3131}}$). Due to its high accuracy and simplicity, it is the standard formula utilized in modern hospital pharmacy systems.
What is the average Body Surface Area for adult men and women?
The average adult human Body Surface Area is considered to be **1.73 m²** (the historical standard baseline used for renal GFR normalization). Specifically, average adult men have a BSA of approximately **1.9 m²**, and average adult women have a BSA of approximately **1.6 m²**.
Why are chemotherapy drugs dosed by BSA rather than body weight (mg/kg)?
Chemotherapeutic agents have extremely narrow therapeutic windows where the toxic dose is very close to the effective therapeutic dose. Metabolic clearance and drug distribution volume correlate more closely with physiological surface area and blood volume than with raw weight, preventing toxic overdosing in obese patients.
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