Loan Calculator

Loan Calculator

Loan Calculator

Result: $0.00

About This calculator

A loan calculator is a tool that helps individuals or businesses estimate the cost of borrowing money. It allows users to input various parameters related to a loan, such as the loan amount, interest rate, loan term, and any additional fees. The calculator then computes the monthly payments, total interest paid, and other relevant financial information.

The key elements typically included in a loan calculator are:

  1. Loan Amount: The total amount of money borrowed.
  2. Interest Rate: The annual interest rate charged on the loan.
  3. Loan Term: The length of time over which the loan will be repaid, usually in years or months.
  4. Payment Frequency: Some calculators allow you to specify whether the payments are made monthly, quarterly, or annually.
  5. Additional Fees: Any extra charges or fees associated with the loan, such as origination fees or closing costs.

How To Use This Calculator ?

  1. Choose Calculation Type:
    • Start by selecting the type of calculation you want to perform from the “Calculation Type” dropdown. Options include:
      • Monthly Payment
      • Loan Amount
      • Interest Rate
      • Loan Term
  2. Enter Values:
    • Depending on the selected calculation type, enter the relevant values in the input fields:
      • For Monthly Payment, input Loan Amount, Interest Rate, and Loan Term.
      • For Loan Amount, input Monthly Payment, Interest Rate, and Loan Term.
      • For Interest Rate, input Monthly Payment, Loan Amount, and Loan Term.
      • For Loan Term, input Monthly Payment, Loan Amount, and Interest Rate.
  3. Click “Calculate”:
    • After entering the required values, click the “Calculate” button.
  4. View Result:
    • The result of the calculation will be displayed below the “Calculate” button, indicating the outcome based on the chosen calculation type.
  5. Reset (Optional):
    • If you want to perform another calculation or start over, you can click the “Reset” button. This clears the input fields and resets the calculation type to its default value.

Example: Suppose you want to calculate the monthly payment for a loan. You would:

  • Choose “Monthly Payment” from the dropdown.
  • Enter the loan amount, interest rate, and loan term.
  • Click “Calculate” to see the estimated monthly payment.

Examples To Try

  1. Monthly Payment Calculation:
    • Example 1: Loan Amount: $20,000, Interest Rate: 3.5%, Loan Term: 48 months
    • Example 2: Loan Amount: $15,000, Interest Rate: 6%, Loan Term: 36 months
    • Example 3: Loan Amount: $30,000, Interest Rate: 4%, Loan Term: 60 months
  2. Loan Amount Calculation:
    • Example 4: Monthly Payment: $400, Interest Rate: 5%, Loan Term: 24 months
    • Example 5: Monthly Payment: $600, Interest Rate: 4.5%, Loan Term: 48 months
    • Example 6: Monthly Payment: $800, Interest Rate: 6%, Loan Term: 36 months
  3. Interest Rate Calculation:
    • Example 7: Monthly Payment: $300, Loan Amount: $10,000, Loan Term: 24 months
    • Example 8: Monthly Payment: $700, Loan Amount: $25,000, Loan Term: 36 months
    • Example 9: Monthly Payment: $500, Loan Amount: $15,000, Loan Term: 48 months
  4. Loan Term Calculation:
    • Example 10: Monthly Payment: $1,000, Loan Amount: $50,000, Interest Rate: 5%
    • Example 11: Monthly Payment: $400, Loan Amount: $20,000, Interest Rate: 4%
    • Example 12: Monthly Payment: $600, Loan Amount: $30,000, Interest Rate: 6%
  5. Diverse Scenarios:
    • Example 13: Loan Amount: $10,000, Interest Rate: 0.5%, Loan Term: 12 months
    • Example 14: Monthly Payment: $300, Loan Amount: $8,000, Loan Term: 24 months
    • Example 15: Monthly Payment: $1,200, Loan Amount: $60,000, Interest Rate: 4%

How This Calculator Function ?

How This Calculator Functions:

The loan calculator operates by executing calculations based on user-inputted values for loan amount, interest rate, loan term, and the selected calculation type. Below is an overview of the functionalities for each calculation type:

Monthly Payment Calculation:

The formula for monthly payment (PMT) is derived from the amortizing loan formula:

PMT = (P * r * (1 + r)^n) / ((1 + r)^n - 1)

Loan Amount Calculation:

To calculate the loan amount (P) based on PMT, r, and n, the formula is rearranged:

P = PMT * ((1 + r)^n - 1) / (r * (1 + r)^n)

Interest Rate Calculation:

The interest rate (r) based on PMT, P, and n is derived from the monthly payment formula:

r = (1/12) * log((1 + PMT/P)^(12n) / ((1 + PMT/P)^(12n) - 1)) * (PMT/P)

Loan Term Calculation:

To calculate the loan term (n) based on PMT, P, and r, the formula is derived from the monthly payment formula:

n = -log(1 - (PMT/P) * r) / (12 * log(1 + r))

User Interaction:

  1. Calculation Type Selection:
    • The user selects the calculation type from the dropdown menu.
  2. Input Values:
    • The user enters values for loan amount, interest rate, and loan term.
  3. Calculation:
    • Clicking “Calculate” triggers a JavaScript function for the selected calculation type.
  4. Result Display:
    • The result is dynamically displayed below the button.
  5. Reset (Optional):
    • Clicking “Reset” clears input fields and resets the calculation type.

Where This Calculator Can Be Used ?

  1. Personal Finance:
    • Individuals can use the calculator to estimate monthly loan payments, determine loan amounts they can afford, or analyze the impact of different interest rates and loan terms on their budget.
  2. Mortgage Planning:
    • Homebuyers or those considering refinancing can use the calculator to estimate monthly mortgage payments, explore various loan terms, and assess the overall cost of a mortgage.
  3. Student Loans:
    • Students and their families can use the calculator to understand the potential impact of interest rates and loan terms on student loan repayments.
  4. Auto Loans:
    • Car buyers can use the calculator to estimate monthly payments, evaluate different loan options, and make informed decisions when financing a vehicle.
  5. Small Business Financing:
    • Entrepreneurs and small business owners can use the calculator to assess loan options, estimate monthly repayments, and make financial decisions related to business loans.
  6. Financial Planning:
    • Financial planners and advisors can use the calculator to assist clients in understanding the financial implications of different loan scenarios.
  7. Educational Settings:
    • The calculator can be used in educational settings to teach students about loan calculations, interest rates, and financial planning.
  8. Banking and Financial Institutions:
    • Financial institutions can provide similar calculators on their websites to assist customers in understanding loan options before applying for loans.
  9. Real Estate Professionals:
    • Real estate agents and professionals can use the calculator to provide clients with quick estimates of mortgage payments and loan affordability.
  10. Budgeting and Decision-Making:
    • Individuals and businesses can use the calculator as a tool for budgeting and making informed financial decisions based on loan-related scenarios.
<!DOCTYPE html>
<html lang="en">
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Loan Calculator</title>
    <link rel="stylesheet" href="styles.css">
    <div id="calculator-container">
        <h2>Loan Calculator</h2>
        <label for="calculationType">Calculation Type:</label>
        <select id="calculationType" onchange="updateLabels()">
            <option value="monthlyPayment">Monthly Payment</option>
            <option value="loanAmount">Loan Amount</option>
            <option value="interestRate">Interest Rate</option>
            <option value="loanTerm">Loan Term</option>

        <div class="input-container">
            <label id="label1" for="input1">Loan Amount ($):</label>
            <input type="number" id="input1" placeholder="Enter loan amount" required>

        <div class="input-container">
            <label id="label2" for="input2">Interest Rate (%):</label>
            <input type="number" id="input2" placeholder="Enter interest rate" required>

        <div class="input-container">
            <label id="label3" for="input3">Loan Term (Months):</label>
            <input type="number" id="input3" placeholder="Enter loan term in months" required>

        <button onclick="performCalculation()">Calculate</button>
        <button onclick="resetForm()">Reset</button>

        <h3 id="result">Result: $0.00</h3>

    <script src="script.js"></script>
  1. <!DOCTYPE html>: Declares the document type and version of HTML being used (HTML5 in this case).
  2. <html lang="en">: Defines the root element of the HTML document and specifies the document language as English.
  3. <head>: Contains metadata about the HTML document, including character set, viewport settings, and the title.
  4. <meta charset="UTF-8">: Specifies the character encoding for the document (UTF-8).
  5. <meta name="viewport" content="width=device-width, initial-scale=1.0">: Sets the viewport properties for responsive design.
  6. <title>Loan Calculator</title>: Defines the title of the HTML document.
  7. <style>: Contains the CSS styles for styling the HTML elements.
  8. <body>: Contains the content of the HTML document, including the loan calculator form and JavaScript code.
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f4f4f4;

#calculator-container {
    width: 35%;
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    animation: glow 3s infinite alternate;
    transition: box-shadow 0.3s ease-in-out;

@keyframes glow {
    0% {
        box-shadow: 0 0 10px rgba(255, 0, 0, 0.5);
    100% {
        box-shadow: 0 0 20px rgba(255, 0, 0, 0.8), 0 0 30px rgba(255, 0, 0, 0.6), 0 0 40px rgba(255, 0, 0, 0.4);

.input-container {
    display: flex;
    flex-direction: column;
    margin-bottom: 16px;

label {
    font-weight: bold;
    text-align: left;
    margin-bottom: 4px;

input {
    width: calc(100% - 16px);
    padding: 10px;
    box-sizing: border-box;
    display: inline-block;
    border: 1px solid #ccc;
    border-radius: 5px;
    transition: border-color 0.3s ease-in-out;
    outline: none;

input:focus {
    border-color: #4caf50;

select {
    width: calc(100% - 50%);
    padding: 8px;
    margin-bottom: 16px;
    box-sizing: border-box;
    transition: transform 0.1s ease-in-out;

select:hover {
    transform: scale(1.05);

button {
    background-color: #4caf50;
    color: #fff;
    padding: 10px;
    border: none;
    border-radius: 4px;
    cursor: pointer;

button:hover {
    background-color: #45a049;

#result {
    font-weight: bold;
  1. body: Applies styles to the entire body of the HTML document.
    • font-family: Specifies the font family for text.
    • margin, padding: Sets margin and padding to zero.
    • display, justify-content, align-items: Utilizes flexbox for centering content vertically and horizontally.
    • min-height: Sets the minimum height of the body to 100% of the viewport height.
    • background-color: Sets the background color.
  2. #calculator-container: Styles for the main container of the loan calculator.
    • width, background-color, padding: Sets dimensions, background color, and padding.
    • border-radius: Adds rounded corners to the container.
    • box-shadow: Creates a shadow effect.
    • animation: Applies a glow animation.
    • transition: Smoothens the transition for box-shadow changes.
  3. @keyframes glow: Defines a keyframe animation for the glow effect.
  4. .input-container: Styles for the input container.
    • display, flex-direction, margin-bottom: Configures a flex container for input elements.
  5. label: Styles for labels.
    • font-weight, text-align, margin-bottom: Sets font weight, text alignment, and bottom margin.
  6. input: Styles for input fields.
    • width, padding, box-sizing, border, border-radius: Defines dimensions, padding, box sizing, and border properties.
    • transition: Smoothens the transition for border color changes.
    • outline: Removes default focus outline.
    • :focus: Styles for focused state.
  7. select: Styles for the dropdown (select) element.
    • width, padding, margin-bottom: Sets dimensions and spacing.
    • box-sizing, transition: Configures box sizing and a scale transition on hover.
  8. button: Styles for buttons.
    • background-color, color, padding, border, border-radius: Defines button appearance.
    • cursor: Sets cursor to pointer.
    • :hover: Styles for hover state.
  9. #result: Styles for the result text.
    • font-weight: Sets bold font.
function updateLabels() {
    const calculationType = document.getElementById('calculationType').value;
    const label1 = document.getElementById('label1');
    const label2 = document.getElementById('label2');
    const label3 = document.getElementById('label3');

    switch (calculationType) {
        case 'monthlyPayment':
            label1.innerText = 'Loan Amount ($):';
            label2.innerText = 'Interest Rate (%):';
            label3.innerText = 'Loan Term (Months):';
        case 'loanAmount':
            label1.innerText = 'Monthly Payment ($):';
            label2.innerText = 'Interest Rate (%):';
            label3.innerText = 'Loan Term (Months):';
        case 'interestRate':
            label1.innerText = 'Monthly Payment ($):';
            label2.innerText = 'Loan Amount ($):';
            label3.innerText = 'Loan Term (Months):';
        case 'loanTerm':
            label1.innerText = 'Monthly Payment ($):';
            label2.innerText = 'Loan Amount ($):';
            label3.innerText = 'Interest Rate (%):';

function performCalculation() {
    const calculationType = document.getElementById('calculationType').value;
    const input1 = parseFloat(document.getElementById('input1').value);
    const input2 = parseFloat(document.getElementById('input2').value);
    const input3 = parseFloat(document.getElementById('input3').value);

    let result;

    switch (calculationType) {
        case 'monthlyPayment':
            result = (input1 * input2 / 100 / 12 * Math.pow(1 + input2 / 100 / 12, input3)) /
                (Math.pow(1 + input2 / 100 / 12, input3) - 1);
        case 'loanAmount':
            result = (input1) / ((input2 / 100 / 12 * Math.pow(1 + input2 / 100 / 12, input3)) /
                (Math.pow(1 + input2 / 100 / 12, input3) - 1));
        case 'interestRate':
            result = Math.pow((input1) / (input2 * input3), 1 / input3 / 12) - 1;
        case 'loanTerm':
            result = -Math.log(1 - (input1 * input2 / 100 / 12) /
                (input3)) / (Math.log(1 + input2 / 100 / 12));
            result = 0;

    document.getElementById('result').innerText = `Result: $${result.toFixed(2)}`;

function resetForm() {
    document.getElementById('calculationType').selectedIndex = 0;
    document.getElementById('input1').value = '';
    document.getElementById('input2').value = '';
    document.getElementById('input3').value = '';
    document.getElementById('result').innerText = 'Result: $0.00';
  1. updateLabels(): Function to dynamically update labels based on the selected calculation type.
  2. performCalculation(): Function to perform the loan calculation based on the selected type and input values.
  3. resetForm(): Function to reset the form to its initial state.

How To Implement

Implementing this Confidence Interval Calculator on WordPress involves a few steps. Here’s a step-by-step guide:

1. Access WordPress Admin Dashboard

Log in to your WordPress admin dashboard.

2. Create a New Page

Navigate to Pages > Add New in the WordPress admin.

Give your page a title, such as “Confidence Interval Calculator.”

3. Switch to HTML Editor

On the page editor, switch to the HTML editor. Look for a tab that says “HTML” or “Code.”

4. Copy HTML Code

Copy the entire HTML code (from <!DOCTYPE html> to the closing </html>) from your index.html file.

5. Paste HTML Code

Paste the copied HTML code into the HTML editor of your WordPress page.

6. Add CSS

Copy the entire CSS code (from the <style> tag in the styles.css file) and paste it into the WordPress page’s HTML editor, preferably within the <head> section.

7. Add JavaScript

Copy the entire JavaScript code (from the <script> tag in the script.js file) and paste it into the WordPress page’s HTML editor, preferably just before the closing </body> tag.

8. Save and Publish

Save the changes to your WordPress page.

Click the “Publish” button to make the page live.

9. View Your Page

Visit the page on your WordPress site to see the Confidence Interval Calculator in action.

Additional Considerations:

  • WordPress Theme Compatibility: Ensure that your WordPress theme supports the custom styles and scripts you’ve added. If needed, you may have to adjust styles to fit seamlessly with your theme.
  • Plugin Usage: If you find that directly pasting HTML, CSS, and JavaScript into the page editor is causing issues, consider using a plugin like “Insert Headers and Footers” to add your custom code.
  • Responsive Design: Check if the calculator layout is responsive. If not, you might need to make adjustments to the CSS for better responsiveness.
  • Debugging: If something doesn’t work as expected, use the browser’s developer tools (usually accessible by right-clicking on the page and selecting “Inspect” or “Inspect Element”) to check for errors in the console tab.

By following these steps, you should be able to implement the Confidence Interval Calculator on your WordPress site. Remember to test the calculator thoroughly to ensure it functions correctly within the WordPress environment.


  1. Q: What is a loan calculator?
    • A: A loan calculator is a financial tool that helps users estimate various aspects of a loan, such as monthly payments, interest rates, loan amounts, or loan terms.
  2. Q: How does a loan calculator work?
    • A: A loan calculator works by taking input values such as loan amount, interest rate, and loan term to calculate and display specific financial results, such as monthly payments or total interest paid.
  3. Q: What are the common types of calculations a loan calculator can perform?
    • A: Common calculations include monthly payments, loan amounts, interest rates, and loan terms.
  4. Q: Why would someone use a loan calculator?
    • A: Individuals use loan calculators to plan and understand the financial implications of a loan, helping them make informed decisions about borrowing.
  5. Q: How does the loan calculator in the provided code determine the type of calculation to perform?
    • A: The calculation type is determined by the user’s selection from a dropdown menu, which triggers the corresponding JavaScript functions.
  6. Q: Can the loan calculator handle different types of loans, such as mortgages or personal loans?
    • A: Yes, the loan calculator can handle different types of loans by allowing users to choose the calculation type based on their specific needs.
  7. Q: What is the purpose of the “Reset” button in the loan calculator?
    • A: The “Reset” button allows users to clear input fields and reset the calculator to its initial state, making it convenient for multiple calculations.
  8. Q: How does the loan calculator handle errors or invalid inputs?
    • A: The provided code does not have extensive error handling. It assumes that users will enter valid numerical inputs. Implementing additional validation can enhance the calculator’s robustness.
  9. Q: Can the loan calculator be customized for different styles or themes?
    • A: Yes, the loan calculator’s appearance can be customized by modifying the CSS styles in the code.
  10. Q: How does the loan calculator address responsiveness for different devices?
    • A: The provided code includes a viewport meta tag and responsive CSS styles, ensuring the calculator adapts to different screen sizes.
  11. Q: Is the loan calculator using a fixed interest rate, or can it handle variable rates?
    • A: The calculator in the provided code assumes a fixed interest rate. Handling variable rates would require additional features and calculations.
  12. Q: How is the loan calculator’s animation achieved?
    • A: The glow effect on the calculator container is implemented using a CSS keyframes animation called “glow.”
  13. Q: Can the loan calculator be integrated into a larger web application?
    • A: Yes, the provided code can be integrated into a larger web application by incorporating its HTML, CSS, and JavaScript components.
  14. Q: What is the significance of the calculationType variable in the JavaScript code?
    • A: calculationType is a variable used to determine the type of loan calculation to perform based on the user’s selection.
  15. Q: How does the loan calculator handle decimal inputs?
    • A: The calculator in the provided code treats inputs as floating-point numbers, allowing for decimal values.
  16. Q: What kind of loans is the loan calculator best suited for?
    • A: The loan calculator is versatile and can be used for various loans, including personal loans, mortgages, and auto loans.
  17. Q: Can the loan calculator handle negative values for loan amount, interest rate, or loan term?
    • A: The provided code does not explicitly handle negative values. Implementing input validation could prevent negative inputs.
  18. Q: How does the loan calculator round the result displayed to the user?
    • A: The result is rounded to two decimal places using the toFixed(2) method in JavaScript.
  19. Q: Are there limitations to the loan calculator’s accuracy in certain scenarios?
    • A: The accuracy depends on the mathematical models used for calculations. In real-world scenarios, additional factors like fees may need consideration.
  20. Q: Can the loan calculator be enhanced to include more advanced features, such as amortization schedules?
    • A: Yes, the calculator’s functionality can be extended to include advanced features like amortization schedules, providing a detailed payment breakdown over time.