Question 1

What is Body Surface Area (BSA)?

Accepted Answer

Body Surface Area (BSA) is the total surface area of a human body. It's often used in clinical settings instead of body weight because it's a more accurate indicator of metabolic mass (the body's need for energy). BSA is commonly used to determine medication dosages, especially for chemotherapy, and to calculate cardiac index.

Question 2

Which BSA formula is most accurate?

Accepted Answer

The Du Bois formula is the most widely used and has been shown to be effective for estimating body fat in both obese and non-obese patients. However, different formulas may be preferred in different clinical settings. Comparing results from multiple formulas can provide a more comprehensive assessment.

Question 3

What is a normal BSA?

Accepted Answer

Average BSA values are: newborn child (0.25 m²), two-year-old child (0.5 m²), ten-year-old child (1.14 m²), adult female (1.6 m²), and adult male (1.9 m²). BSA varies significantly based on height and weight, so there's no single 'normal' value.

Question 4

Why is BSA used for chemotherapy dosages?

Accepted Answer

BSA is used to determine chemotherapy dosages because it's a more accurate indicator of metabolic mass than body weight alone. The effects of chemotherapy dosages determined by BSA measurements remain more consistent than those determined by body weight alone. However, BSA may be less accurate at extremes of height and weight.

Question 5

How is BSA different from BMI?

Accepted Answer

BSA (Body Surface Area) measures the total surface area of the body and is used for clinical purposes like medication dosing. BMI (Body Mass Index) is a measure of body fat based on height and weight and is used to assess weight status. BSA is more accurate for metabolic mass estimation, while BMI is better for general weight assessment. At extremes of height and weight, BMI may be more accurate than BSA.

Question 6

What is 71.84 times body surface area? How do you get BMR from BSA?

Accepted Answer

Basal metabolic rate (BMR) can be estimated from body surface area (BSA) using the formula: BMR = 71.84 × BSA, where BSA is in square meters (m²). So 71.84 * body surface area gives you an estimate of basal metabolic rate in kcal/day. Calculate your BSA on this page, then multiply by 71.84 to get your estimated BMR. This calculator shows the estimated BMR from BSA when you enter your height and weight.