Body Surface Area (BSA) Calculator
Calculate your Body Surface Area (BSA) using the widely accepted Du Bois formula. Enter your height and weight to get an estimate of this important medical measurement.
Calculate Your BSA
What is Body Surface Area (BSA)?
Body Surface Area (BSA) represents the total surface area of the human body. Unlike BMI, which relates weight to height, BSA is often considered a better indicator of metabolic mass because it is less affected by abnormal adipose (fat) mass.
It's primarily used in clinical settings, especially in oncology and critical care, for calculations that require an accurate measure related to the body's metabolic activity.
The Du Bois Formula
This calculator uses the Du Bois formula, one of the most common methods for estimating BSA:
BSA (m²) = 0.007184 × Height(cm)0.725 × Weight(kg)0.425
You simply need to input your height and weight, and the calculator handles the formula.
Applications of BSA
BSA is a critical parameter in various medical applications:
- Drug Dosing: Especially for chemotherapy agents and other drugs with narrow therapeutic indices, dosing based on BSA can be more accurate than weight-based dosing.
- Renal Function: Glomerular filtration rate (GFR), a measure of kidney function, is often normalized to a standard BSA.
- Cardiac Index: Cardiac output (blood pumped by the heart per minute) is sometimes divided by BSA to get the Cardiac Index, allowing comparisons between individuals of different sizes.
- Burn Assessment: Used in estimating fluid requirements for burn patients.
Limitations
While widely used, BSA formulas like Du Bois are estimations. Factors like unusual body composition or specific medical conditions can affect accuracy. Direct measurement is complex and impractical for routine use.
Always consult with healthcare professionals for medical decisions; this calculator is for informational purposes only.
Frequently Asked Questions (FAQ)
What is Body Surface Area (BSA)?
Body Surface Area (BSA) is the calculated total surface area of the human body. It's a physiological measure used primarily in medical contexts rather than general fitness.
How is BSA calculated using the Du Bois formula?
The Du Bois formula is a common method to estimate BSA. It uses height and weight: BSA (m²) = 0.007184 × Height(cm)^0.725 × Weight(kg)^0.425. Our calculator performs this calculation automatically.
Why is BSA important in medicine?
BSA is frequently used to determine appropriate dosages for certain medications, particularly chemotherapy drugs, as metabolic rate and drug clearance are often better correlated with BSA than body weight alone. It's also used in assessing burn severity, fluid requirements, and cardiac output.
Is BSA the same as BMI?
No, they are different measures. BMI (Body Mass Index) assesses weight relative to height squared to categorize weight status (underweight, healthy, overweight). BSA estimates the total external body area, which is relevant for certain physiological processes and medical calculations.
Are there other formulas for calculating BSA?
Yes, besides the Du Bois formula, other formulas exist, such as Mosteller, Haycock, and Gehan & George. The Du Bois formula is one of the most widely used and validated methods.