Do you want to calculate the percentage? If yes, then you can make a simple Percentage calculator using HTML, CSS, and JavaScript. In this article, you have to enter the marks obtained in the first input field and total marks in the second input field for calculating the percentage. After entering values and clicking on the Calculate button, a percentage can be obtained. This very useful project for calculating marks, discounts, etc. The percentage calculator is useful for students, shopkeepers, and for solving basic mathematical problems related to percentages.
File structure
- index.html
- style.css
- script.js
Prerequisites: Basic knowledge of HTML, CSS, and JavaScript needed. The project contains HTML, CSS, and JavaScript files. The HTML file adds structure, followed by styling using CSS and JavaScript adds functionality to it and for making validations to certain parts of the project.
HTML layout is created using the div tags, id attributes, classes, forms, and buttons for submission of the form. It defines the structure of the web page.
By using CSS properties, we will decorate the web page using color, width, height, and position properties that are given as per the requirement in the project. CSS designs the interface of the calculator.
To add functionality to a web page, JavaScript code is used. In this case, two functions, percentage 1() and percentage 2(), are declared and passed to the button via the onclick event. As a result, when the Calculate button is pressed, the result is displayed. We used the method document.getElementById(). It returns the element with the specified ID attribute and returns null if no elements with the specified ID exist.
Formula used:
- What is X percent of Y is given by the formula: X percent of Y =(X/100)* Y
- X is what percent of Y is given by the formula: X is what percent of Y= (X/Y)×100%, where X, Y > 0
HTML
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content=
"width=device-width, initial-scale=1.0">
<title>Percentage Calculator</title>
<link rel="stylesheet" href="style.css" type="text/css" />
</head>
<body>
<h1>Percentage Calculator</h1>
<div>
<h2> What is <input type="number" id="percent" />% of
<input type="number" id="num" />?
</h2>
<button onclick="percentage_1()">Calculate</button><br>
<input type="text" id="value1" readonly />
</div>
<div>
<h2><input type="number" id="num1" />
is what Percent of
<input type="number" id="num2" />?
</h2>
<button onclick="percentage_2()">Calculate</button>
<br>
<input type="text" id="value2" readonly />
</div>
<script type="text/javascript" src="script.js"></script>
</body>
</html>
|
CSS
* {
margin: 0;
padding: 0;
box-sizing: border-box;
font-family: 'Courier New', Courier, monospace;
}
body {
background-color: #f7f7f7;
min-height: 100vh;
display: flex;
justify-content: center;
align-items: center;
flex-direction: column;
}
h1 {
font-weight: 900;
margin-bottom: 12px;
}
div {
width: 480px;
background-color: #fff;
margin: 12px 0;
padding: 24px;
text-align: center;
box-shadow: 2px 2px 8px 2px #aaa;
}
input[type=number] {
width: 84px;
font-size: 18px;
padding: 8px;
margin: 0px 8px 8px 8px;
}
button {
text-transform: uppercase;
font-weight: 900;
font-size: 20px;
margin: 12px 0;
padding: 8px;
cursor: pointer;
letter-spacing: 1px;
}
input[type=text] {
font-size: 22px;
padding: 8px 0;
font-weight: 900;
text-align: center;
background-color: #f7f7f7;
border: 2px solid #ccc;
border-radius: 6px;
}
|
Javascript
function percentage_1() {
var percent = document.getElementById("percent").value;
var num = document.getElementById("num").value;
document.getElementById("value1")
.value = (num / 100) * percent;
}
function percentage_2() {
var num1 = document.getElementById("num1").value;
var num2 = document.getElementById("num2").value;
document.getElementById("value2")
.value = (num1 * 100) / num2 + "%";
}
|
Output:Click here to see live code output
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Last Updated :
16 Feb, 2023
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