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Calculating BMI for Adults in Python 3.0

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Calculating BMI for Adults in Python 3.0

Written by: Christian Thone


What is BMI?

BMI is Body Mass Index, it is a measurment of fat in a human body. By calculating your BMI you can figure out whether or not you are Underweight, Normal Weight, Overweight, or Obese.

How do I find my BMI?

BMI is easy to find, first of you would need the formula, which is simple.

BMI = 703 * [Weight(lbs)] / [Height(Inches)]²

Using this formaula we can find BMI.

Now getting to the code

Start of your code in the file. Type the following code in:

import replit as sys Height = "" Weight = "" BMI = "" UserI = ""

As you can see we are importing replit as sys which will come in handy later. We are also defining a few variables.
Height: Height of the user that will be stored and used later.
Weight: Weight of the user that will be stored and used later.
BMI: BMI of the user which will be calculated later
UserI: User Input which will be used to record data from the user.

Now that you have those variables defined, its time to collect data from the user. Type in the following code to the file:

Height = int(input("Height(inches): ")) Weight = int(input("Weight(lbs): "))

Here you can see that we used the variables: Height and Weight. If you look close you will see that input() is used this is pythons' way of collecting data from the user. If you look even closer you will see int() surrounding each input() this will convert user input into Integers.

Now for the actual math part of this, I will explain every part of the code so you can get a good idea about what is happening here.

In order to calculate BMI we need the formula which is shown at the top of this Tutorial.
Type the following code exactly as shown:

BMI = 703 * Weight / Height ** 2

So as you can see we used a few variables again: BMI, Weight and Height. The two variables Height and Weight store the previous input from the user. You can see the following Mathematical Operators in the formula: /, * and ** I will explain each and their use.

/: Allows us to divide Height and 'Weight'
*: Allows us to multiply the Quotient of Height and Weight by 703 to convert to the metric system.
**: This is the basic math symbol telling the system that we want to have an exponent in the formula.

Now add python print(str(BMI)) to the end of the code.
The str converts BMI to a string so it can print properly without error.
Now that we did that, your code should look something like this:

import replit as sys Height = "" Weight = "" BMI = "" UserI = "" Height = int(input("Height(inches): ")) Weight = int(input("Weight(lbs): ")) BMI = 703 * Weight / Height ** 2 print(str(BMI))


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You can always fancy it up and make it look nice, have instructions, or whatever you would like to put into it. I have mine set up so it checks whether or not you are Underweight, Normalweight, Overweight, or Obese. You can view my project by clicking here
To find the source code click here

Thank you for reading my tutorial, I hope to see you in my next tutorial on Advanced BMI for Adults in Python 3.0

Heres some boring stuff for you to read if you want.
Written and Designed by: Christian Thone |


Program and Coding by: Christian Thone |

Thank you to the team for giving students, and adults the opportunity to teach and learn just like anybody else can.

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