Create a BMI Calculator using Google Forms and Google Sheets

Body Mass Index (BMI) is a numerical measure used to determine whether a person’s weight is appropriate for their height. Using tools like Google Forms and Google Sheets, BMI calculation can be automated, allowing users to quickly input their details and instantly view their BMI and health category.

BMI Index

How to Create a Google Form for BMI Calculation

To create a BMI calculator using Google Forms, the process is divided into three parts as follows:

• Creating a Google Form for BMI Calculation
• Link form submissions to a Google Sheet 
• Establish the BMI calculator

Creating a Google Form for BMI Calculation

Step 1: Open Google on your default web browser

Turn on your default web browser and search for Google.

Step 2: Open Google Forms

From the nine dots menu bar of Google's Home page. Select Google Forms from the list. 

Step 3: Click "Blank Form" to create a new form

On the Forms home page, select "Blank Form" to create a new form to collect the data.

Step 4: Add necessary questions and customize the form

Add the relevant questions per your requirements in the form and mark the required mandatory questions.

Note: 

• BMI calculations require a person's height and weight. Remember that height should be measured in inches and weight in pounds (Ibs).
• Link form submissions to a Google Sheet.

Step 5: Click on the "Response tab"

Once the form has been customized, select the "Response tab" option at the top. 

Step 6: Link form Submissions to a Google Sheet

Select the "Link to Sheets" option in the right corner of the screen. 

Note:

You can select the sheet destinations for responses when you click "Link to Sheets" and choose from two options: creating a new Google Sheet or the existing spreadsheet.

Establishing the BMI calculator

Step 7: Select an empty column for BMI calculation in the sheet

Select any blank column in the Google Sheets to calculate the BMI for each form submission. 

Step 8: Name the selected column

Give a suitable title to the selected column.

Step 9: Enter the formula in the first row

In the very first row, where the patient entries are filled, enter the BMI formula to calculate each patient's BMI. 

In this case, Row 2 is the first line of data, G is the weight column, and H is the height column.

Type in the formula: =G2/(H2)^2*703.

Note:

• For the U.S. imperial measurement system, the formula for BMI is weight / [height]2 x 703.
• Drag the mouse's cursor to the data rows to apply the formula to all the cells. 
• Once you have this formula, you can quickly find each new patient's baseline body mass index (BMI) to use as a reference during your evaluations.

BMI Calculations in Google Sheets

We use Google Sheets to make the following calculations to determine the user's body mass index (BMI).

Age of the respondent

The user's DOB is a mandatory field on the form. The DATEDIF function tells us the age the person is in years.

=MAP(C:C, LAMBDA(c, IF(ROW(c)=1, "Age", 

   IF(ISDATE(c), ROUND(DATEDIF(c, TODAY(), "Y"), 0),))))

BMI Score (kg/m²)

Users are asked to input their height and weight on the form. Every response on the form has its BMI calculated using the MAP function.

=MAP(E:E,F:F, LAMBDA(ht, wt, IF(ROW(wt)=1, "BMI", 

    IF(AND(ISNUMBER(wt),ISNUMBER(ht)), 

      ROUND(wt/(ht/100)^2,2),))))

BMI Category

We use the array function to determine the BMI category.

=ARRAYFORMULA(IF(ROW(J:J)=1, "BMI Category", IF(ISNUMBER(J:J), 

  IF(J:J < 18.5, "Underweight", 

  IF(J:J < 25, "Normal weight", 

  IF(J:J < 30, "Overweight", "Obese"))),)))