The body mass index (BMI) calculator is a measure of body fat based on height and weight that applies to adult men and women. Learn how to calculate your BMI and make a form to measure it easily.
The BMI calculator is a measure that is widely used to assess a person’s weight status and determine whether they are underweight, normal weight, overweight, or obese. It gives out the BMI value and categorizes it based on the provided information by dividing a person’s weight in kilograms by their height in meters squared.


The BMI chart is a popular tool for health professionals and individuals to monitor their weight and make informed decisions about their health.
With Formaloo, you can choose a ready-to-use BMI calculator template or create a new form from scratch. If you select a template, you can customize it to fit your specific needs by adding or removing fields and adjusting the design and settings.
In this article, we will explore how to easily create a BMI test calculator with Formaloo. Let’s start!
Create a BMI test; Easy steps to a powerful tool
1- Create a new form and add fields to your BMI test
Open your dashboard and create a “Blank” form. Next, add the necessary fields to your form to create a BMI calculator. Add fields for the user’s height and weight and a field to display the BMI result. You can set each field’s maximum and minimum acceptable value with the “Edit” button from the top of your form. You can also add any other fields you want to include, such as age, gender, or activity level.
Our BMI test template has three “Number” fields for weight, height, and age. Also, you can add a “Single Choice” field for gender and three “Variable” fields for writing formulas for calculation and total BMI value.


Also, don’t forget to add an ID for each field to calculate the total BMI value in the following steps.
2- Customize your form
You can customize the design and settings of your form to make it look and function the way you want.
Watch this video to learn how to customize your form to the next level.
Customize your BMI test for your business by uploading your logo, using your brand colors, and choosing a relevant background image.
Set up notifications and add custom emails for your form. Integrate with your favorite tools.
Read more about How to integrate Formaloo into 5000+ apps using Zapier.
3- Add formula to calculate BMI value
The BMI formula is weight in kilograms divided by height in meters squared. To add a calculation to your BMI chart, you need two “variable” fields: the first for calculating the height in meters squared and the second for calculating the BMI total value.
From the left side of the editor page, choose “ADD FIELD” and drag the variable field to your page.


You can see how we create the variable fields in this example:
- The first variable field is “height m2”. After writing the field name from the left menu, Change the variable type to “Formula.” To calculate the height in meters squared, set the default value as “height * height.” Now create an “ID” for your variable, which is “heightm2” in this example.
- The second variable is “BMI value” to calculate the total value of your BMI test. The formula is “weight/heightm2,” and the “ID” is “bmivalue.”
Now you have all formulas to calculate the total BMI value.
To show the total value after submitting the form, scroll down to the success message area and write the “ID” of the total BMI value. In this example, the success message is:
Your BMI is {{bmivalue}}


Learn more about how to use answer piping and variables with Formaloo.


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4- Create multiple success messages
The BMI test uses a person’s weight and height to calculate their BMI score, indicating whether they are underweight, normal weight, overweight, or obese.
To show that, you can set up conditional logic to display different success pages depending on the user’s BMI result.
From the left side of your page, drag the “success page” field into your form. Then, write the formula of the total BMI value: Your BMI is {{bmivalue}} in the description for your success messages and add an ID for each one.


Based on the results, you can add images and links and embed videos in your success messages.
And now, it is time to connect your success pages to the total calculation.
Watch this video to learn more about how to create multiple success messages.
5-Add logic for your BMI test results
To show the result of the BMI chart after submitting the form, we have four categories of results;
- Underweight: A BMI below 18.5 is considered underweight.
- Normal weight: A BMI between 18.5 and 24.9 is considered a normal or healthy weight.
- Overweight: A BMI between 25 and 29.9 is considered overweight.
- Obesity: A BMI of 30 or higher is considered obese.
For example, if your weight is 60, and the height is 1.70m, the BMI value based on the formula is 21. So you have a normal weight.
You should create the logic for each page to connect this result to one of the success pages based on the amount.
To create the logic on your form, click on the Logic tab from the top of your editing page and choose “advanced logic.”


Following, you can find a list of all success messages and the logical conditions that lead to each:
1. You are underweight
If the BMI value is less than 18.5, go to the success page after submitting: you are underweight.
2. You have a normal weight
If the BMI value is greater than or equal to 18.5 and less than or equal to 24.9, go to the success page: you have normal weight.
3. You are overweight
If the BMI value is greater than or equal to 25 and less than or equal to 29.9, go to the success page: you are overweight.
4. You are obese
If the BMI value is greater than or equal to 30, go to the success page: you are obese.


That’s it! You’ve just created a custom BMI test with no coding required.
Read this article to learn more about how to use logic in Formaloo.
6- Embed your form on your website
You can embed your BMI form into your website or send the form URL directly to your users.
From your dashboard, right-click on your form, choose “View code & widgets,” and select the code. You can choose from different options like embedded link, iframe, script, widget, or chatbot.


Building a custom BMI in just a few clicks
Creating a BMI test using Formaloo is an easy process that provides valuable insights into an individual’s health. By collecting and analyzing data on height and weight, organizations can better understand the health status of their users and provide personalized recommendations for maintaining a healthy lifestyle.
Formaloo’s user-friendly interface and customizable features make it a powerful tool for building a BMI test. In addition, with the ability to integrate with other health data sources, Formaloo is a valuable resource for organizations looking to promote healthy living and wellness.
You can use multiple success pages on forms to show different outcome pages based on how your users interact with your BMI form. Furthermore, you can use powerful Logic and calculation options to define conditions on how the form should react to the user’s responses in real time.
Also, using the full customization options that Formaloo provides, you can customize your form to the next level.
Sounds fantastic, right? Sign up for free and create your BMI test now!
If you have any questions, check out Formaloo’s support page to find ways you can contact us.
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