create a calculator using html css js

Hey, I am Ajink, and today in this blog, we’re going to create a simple yet functional calculator using HTML, CSS, and JavaScript. This calculator will perform basic arithmetic operations, providing a user-friendly interface for mathematical calculations.

HTML Code:

<!DOCTYPE html>
<html lang="en">
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <link rel="stylesheet" href="style.css">
  <title>Simple Calculator</title>
  <div class="calculator-container">
    <input type="text" id="display" readonly>
    <div class="buttons">
      <button onclick="clearDisplay()">C</button>
      <button onclick="appendToDisplay('7')">7</button>
      <button onclick="appendToDisplay('8')">8</button>
      <button onclick="appendToDisplay('9')">9</button>
      <button onclick="appendToDisplay('/')">/</button>
      <button onclick="appendToDisplay('4')">4</button>
      <button onclick="appendToDisplay('5')">5</button>
      <button onclick="appendToDisplay('6')">6</button>
      <button onclick="appendToDisplay('*')">*</button>
      <button onclick="appendToDisplay('1')">1</button>
      <button onclick="appendToDisplay('2')">2</button>
      <button onclick="appendToDisplay('3')">3</button>
      <button onclick="appendToDisplay('-')">-</button>
      <button onclick="appendToDisplay('0')">0</button>
      <button onclick="appendToDisplay('.')">.</button>
      <button onclick="calculateResult()">=</button>
      <button onclick="appendToDisplay('+')">+</button>
  <script src="app.js"></script>

HTML Code Explanation:

  • The HTML structure includes an input field for displaying the calculator’s input and result, and a set of buttons for digits, operators, and actions.

CSS Code:

body {
  margin: 0;
  font-family: 'Arial', sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  background-color: #f0f0f0;

.calculator-container {
  background-color: #fff;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
  padding: 20px;
  text-align: center;

#display {
  width: 100%;
  padding: 10px;
  margin-bottom: 10px;
  font-size: 20px;

.buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;

button {
  padding: 10px;
  font-size: 18px;
  cursor: pointer;
  border: none;
  border-radius: 4px;
  background-color: #3498db;
  color: #fff;

CSS Code Explanation:

  • The CSS provides styling for the calculator container, display input field, and buttons.

JavaScript Code:

let display = document.getElementById('display');

function appendToDisplay(value) {
  display.value += value;

function clearDisplay() {
  display.value = '';

function calculateResult() {
  try {
    display.value = eval(display.value);
  } catch (error) {
    display.value = 'Error';

JavaScript Code Explanation:

  • The JavaScript code defines functions for appending values to the display, clearing the display, and calculating the result using the eval function.
  • Error handling is included to display “Error” in case of invalid calculations.


In this blog, we successfully built a simple calculator using HTML, CSS, and JavaScript. Users can perform basic arithmetic operations with a user-friendly interface. Don’t forget to subscribe to my YouTube channel at for more exciting tutorials.

Thanks for reading, and if you have any doubts, feel free to comment!

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