50 HTML CSS JavaScript Projects - Build a Modern BMI Calculator with HTML, CSS & JavaScript (Step-by-Step Tutorial)

Build a Modern BMI Calculator with HTML, CSS & JavaScript (Step-by-Step Tutorial) Build a fully functional BMI Calculator from scratch while mastering modern HTML, CSS, and JavaScript in a single, hands-on project. In this step-by-step tutorial, we start by explaining how BMI (Body Mass Index) works, how height in centimeters and weight in kilograms are used in the formula, and how to turn that logic into a real web application. You will see how to create clean input fields with default values, a responsive Compute BMI button, and a result area that instantly displays both the BMI value and the corresponding weight condition. As we walk through underweight, normal, overweight, and obesity categories, you’ll understand how conditional logic drives dynamic user feedback. By the end of this part, you’ll have a clear idea of how a real-life health tool can be implemented directly in the browser. Next, we construct the full HTML structure for our BMI calculator interface using a clear and organized workflow inside Visual Studio Code. You’ll learn how to set up the project folder, create the index.html file, configure essential meta tags, and name your page correctly for better usability and SEO. We carefully build the layout: a main container, headings, labels, numeric input fields for height and weight, a disabled result field, and an info section for the live weight condition status. Each element is purposefully given classes and IDs so that styling and scripting become intuitive and maintainable. This section helps you understand semantic structure, scalability, and how a professional front-end setup makes the rest of the project smooth and efficient. Then we bring the design to life with a neumorphism-inspired CSS style and powerful JavaScript functionality to create a polished, interactive user experience. You’ll style a glassy, centered container with a responsive gradient background, customize inputs, and add smooth hover effects to the button to make the UI feel modern and engaging. In JavaScript, we link our script correctly, attach event listeners, pull values from inputs, apply the BMI formula correctly (including unit conversion), and display the calculated BMI directly in the result field. Using if and else-if statements, we dynamically update the “weight condition” text to show underweight, normal, overweight, or obesity based on real ranges, reinforcing core programming concepts like DOM manipulation, events, and conditional logic. If you find this tutorial helpful, don’t forget to like the video, drop your questions or improvements in the comments, and subscribe for more practical JavaScript projects that strengthen your portfolio and problem-solving skills. source code: https://www.100jsprojects.com/project/bmi-calculator #javascript #bmicalculator #webdevelopment timestamp: 0:00 - Preview - BMI Calculator 1:50 - HTML - BMI Calculator 14:21 - CSS - BMI Calculator 27:20 - JavaScript - BMI Calculator