Advanced Calculator Using HTML CSS JavaScript | Free Source Code + Live Demo

Build an advanced scientific calculator using HTML, CSS, and JavaScript. Includes source code, live demo, and responsive design. Fast | Free | Secure | No Watermark – perfect for students and developers.

Sunday, June 8, 2025
Advanced Calculator Using HTML CSS JavaScript | Free Source Code + Live Demo

 Create an Advanced Feature Calculator Using HTML, CSS, and JavaScript | Free Source Code + Live Demo

If you're looking to build an advanced calculator using pure HTML, CSS, and JavaScript, you're in the right place! In this blog post, we’ll walk through the creation of a feature-rich calculator that goes far beyond basic math. Whether you're a student, developer, or enthusiast, this open-source project will help you understand DOM manipulation, event handling, and mathematical logic in JavaScript.

🎯 What Is This Project About?

This project is a web-based Advanced Feature Calculator designed to perform both basic and scientific calculations in a browser. It supports all essential arithmetic operations as well as trigonometric functions, square roots, logarithms, and exponentiation. This calculator is responsive, fast, and works seamlessly on both desktop and mobile devices.

πŸ” Features of the Calculator

βœ… Basic Operations

  • Addition +, Subtraction βˆ’, Multiplication Γ—, Division Γ·

βœ… Advanced Math Functions

  • Trigonometric: sin(), cos(), tan()

  • Logarithmic: log()

  • Square Root: √

  • Exponents: ^

βœ… Built-in Constants

  • Pi Ο€, Euler’s number e

βœ… Extras

  • Backspace and clear button

  • Keyboard input support

  • Responsive and mobile-friendly design

  • No watermarks, no ads – completely free

πŸ‘¨β€πŸ’» Technologies Used

  • HTML5 – For layout and structure

  • CSS3 – For styling and responsiveness

  • JavaScript – For logic and functionality

This project is written with clean, commented code – ideal for beginners and intermediates who want to learn by doing.

🎬 Live Demo

πŸ‘‰ Experience the calculator in action before diving into the code.

πŸ’Ύ Source Code

You can download the full source code below and modify it as per your requirements.

πŸ”½ Download Source Code (ZIP)
πŸ“ Includes: index.html, style.css, script.js

HTML Code

<div class="calculator">
  <input type="text" id="display" class="display" disabled>
  <div class="buttons">
    <button onclick="clearDisplay()" class="clear">C</button>
    <button onclick="backspace()">⌫</button>
    <button onclick="insert('Ο€')">Ο€</button>
    <button onclick="insert('e')">e</button>
    <button onclick="insert('/')">Γ·</button>

    <button onclick="insert('7')">7</button>
    <button onclick="insert('8')">8</button>
    <button onclick="insert('9')">9</button>
    <button onclick="insert('*')">Γ—</button>
    <button onclick="insert('^')">^</button>

    <button onclick="insert('4')">4</button>
    <button onclick="insert('5')">5</button>
    <button onclick="insert('6')">6</button>
    <button onclick="insert('-')">βˆ’</button>
    <button onclick="insert('sqrt(')">√</button>

    <button onclick="insert('1')">1</button>
    <button onclick="insert('2')">2</button>
    <button onclick="insert('3')">3</button>
    <button onclick="insert('+')">+</button>
    <button onclick="insert('log(')">log</button>

    <button onclick="insert('0')" class="zero">0</button>
    <button onclick="insert('.')">.</button>
    <button onclick="calculate()" class="equals">=</button>
    <button onclick="insert('sin(')" class="function">sin</button>
    <button onclick="insert('cos(')" class="function">cos</button>
    <button onclick="insert('tan(')" class="function">tan</button>
    <button onclick="insert('(')">(</button>
    <button onclick="insert(')')">)</button>
  </div>
</div>

CSS Code

  
    body {
      background: #1e1e2f;
      font-family: 'Segoe UI', sans-serif;
      color: white;
      display: flex;
      justify-content: center;
      align-items: center;
      height: 100vh;
      margin: 0;
    }

    .calculator {
      background: #2e2e3f;
      border-radius: 15px;
      padding: 20px;
      width: 350px;
      box-shadow: 0 10px 25px rgba(0,0,0,0.5);
    }

    .display {
      background: #111;
      border: none;
      color: #0f0;
      font-size: 28px;
      padding: 15px;
      width: 100%;
      border-radius: 10px;
      text-align: right;
      margin-bottom: 20px;
    }

    .buttons {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      gap: 10px;
    }

    .buttons button {
      padding: 15px;
      font-size: 18px;
      border: none;
      border-radius: 8px;
      background: #444;
      color: white;
      cursor: pointer;
      transition: background 0.2s;
    }

    .buttons button:hover {
      background: #555;
    }

    .buttons button.function {
      background: #6c63ff;
    }

    .buttons button.equals {
      background: #28a745;
    }

    .buttons button.clear {
      background: #dc3545;
    }

    .buttons button.zero {
      grid-column: span 2;
    }

JavaScript Code

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

  function insert(value) {
    display.value += value;
  }

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

  function backspace() {
    display.value = display.value.slice(0, -1);
  }

  function calculate() {
    let expression = display.value
      .replace(/Ο€/g, 'Math.PI')
      .replace(/e/g, 'Math.E')
      .replace(/sin\(/g, 'Math.sin(')
      .replace(/cos\(/g, 'Math.cos(')
      .replace(/tan\(/g, 'Math.tan(')
      .replace(/log\(/g, 'Math.log10(')
      .replace(/sqrt\(/g, 'Math.sqrt(')
      .replace(/\^/g, '**');

    try {
      display.value = eval(expression);
    } catch {
      display.value = 'Error';
    }
  }

  // Optional: Keyboard support
  document.addEventListener('keydown', (e) => {
    const key = e.key;
    if (/\d|\+|\-|\*|\/|\(|\)|\./.test(key)) {
      insert(key);
    } else if (key === 'Enter') {
      calculate();
    } else if (key === 'Backspace') {
      backspace();
    } else if (key === 'Delete') {
      clearDisplay();
    }
  });

PHP Code

NO Need
Show Result

πŸš€ How to Use

  1. Download or copy the source code.

  2. Open index.html in your browser.

  3. Start calculating – it’s that easy!

You can also integrate this calculator into your own project or website.

πŸ› οΈ Future Improvements (Optional Ideas)

  • Add history log of previous calculations

  • Light/Dark mode toggle

  • Support for graph plotting using Canvas or Chart.js

  • Theme customizer or color switcher


    Performance Optimized

    This calculator loads instantly, has no external dependencies, and is built using vanilla JavaScript. That means fast load times, clean HTML structure, and mobile-first responsiveness, which are all great for search engine visibility.

    πŸ“£ Why Share This on AlertCampusGenius.com?

    At AlertCampusGenius, we believe in sharing practical, ready-to-use tools and educational code for students, freelancers, and developers. This calculator project aligns perfectly with our mission: learn, build, and grow together.

    πŸ“Œ Conclusion

    This Advanced Feature Calculator is a perfect blend of simplicity and functionality. Whether you're a beginner in JavaScript or someone building your web portfolio, this project offers real-world practice and value.


    Frequently Asked Questions (FAQ)

    1. What features does the Advanced Feature Calculator support?

    The calculator supports basic arithmetic operations like addition, subtraction, multiplication, and division, as well as advanced mathematical functions including trigonometric functions (sin, cos, tan), logarithms (log), square roots (√), exponentiation (^), and constants like Ο€ (pi) and e.

    2. Is this calculator mobile-friendly?

    Yes! The calculator is fully responsive and works seamlessly across all devices, including smartphones, tablets, and desktop browsers.

    3. Can I use the calculator with my keyboard?

    Absolutely. The calculator supports keyboard input for numbers, operators, and functions. You can also use Enter to calculate, Backspace to delete the last character, and Delete to clear the display.

    4. Is the source code free to use and modify?

    Yes, the source code is 100% free and open for anyone to download, use, and customize for personal or educational projects.

    5. How do I run the calculator on my own device?

    Simply download or copy the source code files, open the index.html file in any modern web browser, and start calculating right awayβ€”no installation required.

    6. Can I add more features to this calculator?

    Definitely! The code is written clearly and commented for easy customization. You can add features like calculation history, dark mode, graph plotting, or even integrate it into your own projects.

    7. Does this calculator require an internet connection to work?

    No, it works completely offline since all the logic runs client-side using JavaScript in your browser.

    8. What browsers support this calculator?

    It works perfectly on all modern browsers, including Google Chrome, Mozilla Firefox, Microsoft Edge, Safari, and Opera.

    If you have more questions or need help customizing the calculator, feel free to leave a comment below!

    Don't forget to bookmark this page, share it with your friends, and stay tuned for more awesome open-source projects.






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