Welcome to Coding Torque. In this blog, we are going to create a BMI Calculator using HTML, CSS & JavaScript. You should create this project if you are a beginner and learning JavaScript. This project simply takes height and weight as input and returns BMI as output.
Before we start, here are some more JavaScript projects for you to practice:
1. Filter Cards using JavaScript
2. Typing Effect using JavaScript
3. Email Validator using JavaScript
4. Tip Calculator using JavaScript
5. QR Code Generator using JavaScript
I would recommend you don't just copy and paste the code, just look at the code and type by understanding it.
Let's go step by step:
Step 1: HTML Code
Starter Template
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- CSS -->
<link rel="stylesheet" href="style.css">
<title>BMI Calculator using JavaScript with Source Code - @code.scientist x @codingtorque</title>
</head>
<body>
<!-- Further code here -->
<script src="script.js"></script>
</body>
</html>Paste the below code in your <body> tag
<div class="container">
<h2 style="text-align: center;">BMI Calculator</h2>
<form>
<p class="inputs">
<label>Height (CM): </label>
<input type="number" id="height" min="1">
</p>
<p class="inputs">
<label>Weight (KG): </label>
<input type="number" id="weight" min="1">
</p>
<button class="calcBtn">Calculate</button>
<div style="margin-top: 20px;">Your BMI is: <p id="results"></p>
</div>
<p id="message"></p>
</form>
</div>Output Till Now
Step 2: CSS Code
Create a file style.css and paste the code below.
@import url("https://fonts.googleapis.com/css2?family=Poppins&family=Potta+One&display=swap");
* {
margin: 0;
padding: 0;
box-sizing: border-box;
font-family: "Poppins", sans-serif;
}
body {
display: flex;
align-items: center;
justify-content: center;
background: #0f172a;
}
.container {
width: 22rem;
margin-top: 8rem;
background-color: white;
border-radius: 10px;
padding: 30px;
}
.inputs {
display: flex;
flex-direction: column;
margin: 15px 0;
}
.inputs input {
outline: none;
height: 30px;
}
#results {
font-size: 20px;
text-align: center;
color: blue;
}
.calcBtn {
width: 100%;
padding: 8px 0;
margin-top: 10px;
border-radius: 5px;
border-style: none;
background: #2563eb;
color: #fff;
cursor: pointer;
font-size: 20px;
}
#message {
text-align: center;
}
Output Till Now
Step 3: JavaScript Code
Create a file script.js and paste the code below.
const form = document.querySelector('form');
form.addEventListener('submit', function (e) {
e.preventDefault();
const height = parseInt(document.querySelector('#height').value);
const weight = parseInt(document.querySelector('#weight').value);
const results = document.querySelector('#results');
const message = document.querySelector('#message');
if ((height === '') || (height < 0) || (isNaN(height))) {
//NaN !== NaN
results.innerHTML = "Please provide a valid height";
} else if (weight === '' || weight < 0 || isNaN(weight)) {
results.innerHTML = "Please provide a valid weight";
} else {
// Calculate BMI
const bmi = (weight / ((height * height) / 10000)).toFixed(2);
// Display the results
results.innerHTML = `<span>${bmi}</span>`
// Display End Message
if (bmi < 18.6) {
message.innerHTML = "You are underweight";
} else if (bmi > 18.6 && bmi < 24.9) {
message.innerHTML = "Normal"
} else if (bmi > 24.9) {
message.innerHTML = "You are Overweight"
}
}
});
If you want me to code any project or post any specific post, feel free to DM me at IG @code.scientist or @codingtorque
If you have any doubts or any project ideas feel free to Contact Us
Hope you find this post helpful💖
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