What is BSA?

In medical terms, BSA stands for the body surface area.

BSA is the calculated surface area of the human body. It is an important measurement that has a lot of applications in the medical domain.

For instance, BSA is used to calculate chemotherapy dosages for cancer patients.

Along with that, BSA is an essential factor that helps calculate various medical indicators as well.

Medical calculations for Cardiac Index (CI), Stroke Volume Index (SVI), Systematic Vascular Resistance Index (SVRI), and Pulmonary Vascular Resistance Index (PVRI) rely on BSA calculation.

You can’t get the values for these medical indicators if you don’t know the BSA of a person.

BSA calculation is quite tricky. There are various formulas out there that you can use to calculate the BSA.

If you don't want to go through the hassle of manual BSA calculation, the BSA Calculator would be an excellent tool.

About BSA Calculator

Body Surface Area (BSA) Calculator is a free online tool that allows you to figure out your BSA based on your height and weight.

You need to enter your height and weight in the BSA calculator, and the tool gives you the BSA value based on your input.

The BSA calculator is quite versatile as it offers multiple options for the input.

For example, you can enter your height in feet/inches, centimeters, and even meters.

You can add it as input in the pounds, kgs, ounces, ton, and gram values for the weight.

When you enter these values in the calculator, it gives you the BSA in terms of m².

The BSA Calculator is incredibly fast and powerful. This tool uses the various BSA calculation formulas to bring you the best possible results for your BSA value. 

How to Use the BSA Calculator

Here is how you can use the BSA Calculator to find your body surface area:

• Choose your preferred input format for Height and Weight
• Enter your height in the calculator
• Enter your weight in the calculator
• Click on the Calculate button on the BSA calculator

The BSA calculator performs its calculations and gives you the BSA value as output when you hit the calculate button. 

Why is Calculating Body Surface Area important?

BSA calculation has numerous applications in the field of medical science.

There are a lot of medical assessments that rely on BSA. One of its most important applications is in determining the appropriate drug dosages for patients.

For example, doctors use the BSA to determine the correct dose of chemotherapy for a patient. This makes BSA calculation immensely useful for cancer patients.

 

 

Clinical Significance of Body Surface Area

The clinical signific of BSA is well-documented. BSA is quite important in pharmacology, and it is also used for various physiologic data measurements.

Research indicates that chemotherapy results were prominent for individuals who were treated with chemo doses based on the BSA.

This mode of treatment has proven itself to be more consistent and effective relative to the chemotherapy doses measurement based on bodyweight.

The importance of BSA calculation is significant for burn injury patients as well.

It allows medical professionals to accurately determine the percentage of body area where the patient has received the burns.

Here are some essential medical assessments that rely on BSA for their calculation:

Cardiac Index (CI)

Cardiac Index is an essential medical calculation. If you want to know the CI of a patient, you can’t do it without calculating the BSA first.

Cardiac Index: CI = Cardiac Output / Body Surface Area (BSA)

Stroke Volume Index (SVI)

For calculating the Stroke Volume Index, you need to divide the stroke volume with body surface area.

Stroke Volume Index: SVI = Stroke Volume / Body Surface Area

Systematic Vascular Resistance Index (SVRI)

The systematic vascular resistance index is calculated by multiplying the Systematic Vascular index with the BSA.

Systematic Vascular Resistance Index: SVRI = SVR * BSA

Pulmonary Vascular Resistance Index (PVRI)

The pulmonary vascular resistance index is calculated by dividing the PVR with BSA.

PVR Index: PVRI = PVR / BSA

Average BSAs for Kids & Adults

Doctors use BSA for clinical purposes as it is a comparatively accurate indicator of body mass compared with bodyweight.

The average BSA values vary throughout the different stages of human development.

Here is the Average BSAs table that you can use to know what your BSA should be:

• The BSA for a newborn child of 0.25m²
• The BSA for a 2-year old child is 0.5m²
• The BSA for a 10-year old child is 1.14m²
• The BSA for an adult female is 1.6m² 
• The BSA for an adult male is 1.9m²

These are the average BSA values during different life stages for a person.

Doctors look at these values and compare your specific one to figure out the best possible mode of treatment for you. 

BSA Calculation Formulas

Over the years, there have been many formulas introduced to find the BSA. All these formulas deliver almost the same results.

For manual Body Surface Area calculation, you need to be aware of these formulas.

The BSA calculator helps you automate the calculation and saves you a lot of time and effort.

But if you want to learn manual BSA calculation, then this section is for you.

You can use any of the below formulas to calculate the Body Surface Area.

All these formulas require you to know the weight in Kgs and Height in cm to find the BSA. Also, you get the resulting BSA in m².

So, if you have the weight and height in any other form of measurement, you should convert them to kg and cm, respectively. 

Here are the standard BSA calculation formulas that you can use to find your body surface area:

Du Bois Formula

The Du Bois Formula is the most commonly used approach for calculating BSA.

This was the first formula for finding BSA, which Du Bois developed in 1916.

Here is the Du Bois Formula for finding Body Surface Area:

Body Surface Area (BSA) = 0.007184 × W^0.425 × H^0.725

The W and H stand for weight and height in this formula. So, if you know your weight and height, you can use them to find the BSA.

Mosteller Formula

Mosteller Formula is a lot simpler than the Du Bois formula.

This is because the values are repetitive in the formula, so you don't need to memorize a lot of different weights.

Body Surface Area = 0.016667 × W^0.5 × H^0.5

So, you need to take your weight, height and raise them to the power of 0.5. After that, you need to multiply the values as shown above. 

Haycock Formula

The Haycock Formula is also based on the product of weight, height, and the value 0.024265.

Here is the formula for BSA calculation developed by Haycock:

Body Surface Area = 0.024265 × W^0.5378 × H^0.3964

Gehan and George Formula 

The Gehan and George Formula is another way to calculate the body surface area. Here are the values used in the Gehan and George Formula:

Body Surface Area = 0.0235 × W^0.51456 × H^0.42246

Fujimoto Formula

Fujimoto BSA formula is another approach that you can use for finding the body surface area. The formula follows the same pattern as the ones mentioned before.

Here is how you can use the Fujimoto Formula to find the BSA:

Body Surface Area  = 0.008883 × W^0.444 × H^0.663

Boyd Formula

The Boyd formula looks a little bit complicated. But still, it works fine when it comes to BSA calculation. So, for the sake of completion, we will present it here so that you can try it out if you want to.

Here is how you can use the Boyd Formula to find the Body Surface Area:

Boyd BSA Calculation Formula = 0.03330 × W^{(0.6157 - 0.0188 × log10(W)} × H^0.3

Takahira Formula

Takahira Formula for BSA is a commonly used approach for finding the body surface area.

Here is how you can use the Takahira Formula to find the BSA:

Body Surface Area = 0.007241 × W^0.425 × H^0.725

Schlich Formula

Schlich Formula uses a slightly different approach for finding the BSA. With this formula. Schlich Formula offers 2 equations separately for finding the BSA for Men and Women.

Men Body Surface Area = 0.000579479 × W^0.38 × H^1.24

Women Body Surface Area = 0.000975482 × W^0.46 × H^1.08

 

The BSA Calculator works on these standard formulas to provide you with accurate body surface area values.

You don't need to do any calculations manually. You can add your height and weight to the calculator, and it will give you the estimated BSA value.

So, if you want to find your BSA and don't want to use the manual approach, the BSA calculator will be your best option.

FAQs

1. How to calculate the body surface area?

You can use the BSA Calculator to calculate the body surface area. You can enter your height and weight in the calculator, and it will give you the BSA value based on your input.

2. Why do you need to calculate body surface area?

BSA calculation is quite helpful as it helps determine the right amount of drug dosages for patients. It is excellent for burn injury patients because doctors can use the BSA to figure out the percentage of burns on the body and come up with better treatment options.

3. What BSA is considered overweight?

According to a credible study, the BSA between 1.99 +/- 0.16m² is considered overweight. This study explains the BSAs for normal and obese people as well that you can check out.

4. Why is the BSA used for chemotherapy?

The chemo dosage is determined with the help of BSA. Doctors use BSA to find out the dosages of chemo that they need to administer to their patients. 

Since patients usually have different BSAs, there is no way to pinpoint the exact dosage given to a patient without knowing their BSA.

5. What is the difference between body surface area & body mass index?

Body Surface Area is the calculated surface area of a human body.

Body Surface can be calculated using various formulas such as Du Bois, Mosteller, Boyd, Haycock, Gehan, and George Formulas. There are many other formulas for calculating BSA that you can also find out there.

The BSA calculation formulas are the same for both genders.

The Body Mass Index or BMI is a person’s mass divided by the square of their height. You can either use the BMI calculation formula or a BMI chart to find the body mass index. 

You can calculate the BMI for both genders using the same body mass index calculation formulas.

6. What is the BSA test about?

BSA or body surface area is an important measurement that is widely used in the medical field. This test is essential for cancer patients as it helps doctors figure out the right amount of chemotherapy dosages for the patients.