Percentage calculator

Percentage Calculator

Percentage Calculator

Table of Contents:



Part: The portion you want to find the percentage of.

Whole: The whole or total amount.

New Value and Old Value: Values for calculating percentage change.

Percentage: The percentage to apply for discount/markup or calculate a portion of a number.

Number: The total number for calculating a percentage of it.

Measured Value and Actual Value: Values for calculating percentage error.

Rate: The rate for compound interest calculation.

Time: The time for compound interest calculation.

What Is Percentage Calculator

Would you like an easy way to figure out the percentage of a value without doing the math yourself? If yes, you can use our percentage calculator—it’s a simple tool designed to make calculating percentages easy.
Our online percentage calculator is user-friendly, so whether you’re using a smartphone or a desktop, you can calculate percentages without any trouble. Best of all, it’s free! You won’t be charged anything, no matter how often you use it.
Feel free to start using our online percentage finder today for all your percentage calculations!

How To Use

Understanding the Calculator Inputs:

  • The calculator has various input fields, each labeled for a specific purpose. For example, “Part,” “Whole,” “New Value,” “Old Value,” “Percentage,” “Number,” “Measured Value,” “Actual Value,” “Rate,” and “Time.”
  • You can input values into these fields based on the type of percentage calculation you want to perform.

Performing Different Calculations:

  • The calculator supports different types of percentage calculations, and there are buttons at the bottom for each type. The available calculations include Basic Percentage, Percentage Change, Discount/Markup, Percentage of a Number, Percentage Error, and Compound Interest.

Using the Calculator Buttons:

  • Click on the appropriate button based on the type of calculation you want to perform. For example, if you want to calculate the Basic Percentage, click on the “Basic Percentage” button.

Viewing the Result:

  • The result of the calculation will be displayed below the buttons. It will show the calculated percentage result with two decimal places.

Resetting the Form:

  • If you want to reset the calculator and clear all input values and results, you can click on the “Reset” button.

Tips for Inputs:

  • Below the result section, there are tips explaining the purpose of each input field. It provides guidance on what each input represents for different types of calculations.


For a Basic Percentage calculation, you can enter the “Part” and “Whole” values and click on the “Basic Percentage” button to see the result.

Basic Percentage:

Suppose you want to find what percentage a certain value (part) is of another value (whole).
Part: 25
Whole: 100
Click on “Basic Percentage” button to get the result.

Percentage Change:

If you have an old value and a new value, and you want to find the percentage change.
Old Value: 50
New Value: 75
Click on “Percentage Change” button to get the result.


Calculate the final price after a certain percentage discount or markup.
Original Price: 80
Percentage: 20 (for a 20% markup)
Click on “Discount/Markup” button to get the result.

Percentage of a Number:

Find a certain percentage of a given number.
Percentage: 15
Number: 200
Click on “Percentage of a Number” button to get the result.

Percentage Error:

Calculate the percentage error between a measured value and an actual value.
Measured Value: 80
Actual Value: 100
Click on “Percentage Error” button to get the result.

Compound Interest:

Determine the compound interest based on principal, rate, and time.
Principal: 1000
Rate: 5
Time: 2
Click on “Compound Interest” button to get the result.

Code For Tool Implementation

<!DOCTYPE html>
<html lang="en">
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Percentage Calculator</title>
  <link rel="stylesheet" href="styles.css">

  <div class="container">
    <label for="part">Part:</label>
    <input type="text" id="part" placeholder="Enter part">

    <label for="whole">Whole:</label>
    <input type="text" id="whole" placeholder="Enter whole">

    <label for="newVal">New Value:</label>
    <input type="text" id="newVal" placeholder="Enter new value">

    <label for="oldVal">Old Value:</label>
    <input type="text" id="oldVal" placeholder="Enter old value">

    <label for="percentage">Percentage:</label>
    <input type="text" id="percentage" placeholder="Enter percentage">

    <label for="number">Number:</label>
    <input type="text" id="number" placeholder="Enter number">

    <label for="measuredVal">Measured Value:</label>
    <input type="text" id="measuredVal" placeholder="Enter measured value">

    <label for="actualVal">Actual Value:</label>
    <input type="text" id="actualVal" placeholder="Enter actual value">

    <label for="rate">Rate:</label>
    <input type="text" id="rate" placeholder="Enter rate">

    <label for="time">Time:</label>
    <input type="text" id="time" placeholder="Enter time">

  <button onclick="calculateBasicPercentage()">Basic Percentage</button>
  <button onclick="calculatePercentageChange()">Percentage Change</button>
  <button onclick="calculateDiscountMarkup()">Discount/Markup</button>
  <button onclick="calculatePercentageOfNumber()">Percentage of a Number</button>
  <button onclick="calculatePercentageError()">Percentage Error</button>
  <button onclick="calculateCompoundInterest()">Compound Interest</button>
  <button class="reset" onclick="resetForm()">Reset</button>

  <div id="result"></div>

  <script src="script.js"></script>

This HTML code defines the structure of a web page for a Percentage Calculator. Let me break down the different sections:

  1. <!DOCTYPE html>: This is the document type declaration, specifying the version of HTML (in this case, HTML5) that the document is using.
  2. <html lang="en">: This is the root element of the HTML document, and it sets the language of the document to English.
  3. <head>: This section contains meta-information about the HTML document, such as character set, viewport settings, title, and external stylesheet link.
    • <meta charset="UTF-8">: Specifies the character encoding for the document as UTF-8.
    • <meta name="viewport" content="width=device-width, initial-scale=1.0">: Sets the viewport configuration for responsive design.
    • <title>Percentage Calculator</title>: Sets the title of the web page.
    • <link rel="stylesheet" href="styles.css">: Links an external stylesheet named “styles.css” to apply styling to the HTML elements.
  4. <body>: This is the main content of the HTML document.
    • The content is organized within a <div> element with the class “container”. Inside this container, there are several sets of labels and input elements for different types of percentage calculations.
    • Following the input fields, there are several <button> elements. Each button has an onclick attribute that triggers a specific JavaScript function when clicked.
    • The JavaScript functions (e.g., calculateBasicPercentage(), calculatePercentageChange(), etc.) are expected to be defined in an external script file named “script.js”, which is linked at the end of the document.
    • There is also a <div> element with the id “result” where the calculated results will be displayed.
  5. <script src="script.js"></script>: This script tag links an external JavaScript file named “script.js” to the HTML document. The actual logic for calculating percentages and handling button clicks is expected to be defined in this script file.

Overall, this HTML code sets up a user interface for a percentage calculator and includes placeholders for user input.

body {
  font-family: 'Arial', sans-serif;
  background-color: #f5f5f5;
  margin: 0;
  justify-content: center;
  align-items: center;
  height: flex-start;

.container {
  display: grid;
  grid-template-columns: repeat(4, 0.2fr);
  background: linear-gradient(to right, #00c6fb, #005bea);
  border-radius: 15px;        
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.2);       
  padding: 30px;        
  text-align: center;
  max-width: 700px;
  width: 100%;
  margin: 10px;

/* Form Styles */
form {
  display: flex;
  flex-direction: column;
  gap: 15px;

label {
  display: block;
  margin-top: 15px;
  color: #000000;
  font-size: 20px;

input {
  width: flex-left;
  padding: 9px;
  margin-top: 10px;
  border: 2px solid #000000;
  border-radius: 8px;
  outline: none;
  text-align: center;
  font-size: 8px;
  transition: border-color 0.3s, transform 0.2s;

input:hover {
  border-color: #27ae60;
  transform: translateY(-2px);

button {
  padding: 10px;
  margin-bottom: 10px;
  cursor: pointer;
  background-color: #27ae60;
  color: #ecf0f1;
  font-size: 16px;
  border: none;
  border-radius: 8px;
  transition: background-color 0.3s, transform 0.2s, box-shadow 0.3s;
  box-shadow: 0px 6px 8px rgba(0, 0, 0, 0.2);

button:hover {
  background-color: #219651;
  transform: translateY(-3px);
  box-shadow: 0px 8px 10px rgba(0, 0, 0, 0.3);

button:active {
  transform: translateY(3px);

button.reset {
  background-color: #e74c3c;
  margin-left: 20px;

#result {
  margin-top: 30px;
  font-size: 24px;
  color: #000000;

This CSS code provides styling rules for the HTML elements defined in the previous code snippet. Let’s break down the styles for different sections:

  1. Body Styles:
    • font-family: 'Arial', sans-serif;: Sets the font family for the entire document to Arial or a generic sans-serif font.
    • background-color: #f5f5f5;: Sets the background color of the entire page to a light gray (#f5f5f5).
    • margin: 0;: Removes any default margin on the body element.
    • justify-content: center; align-items: center;: Centers the content both horizontally and vertically within the body.
    • height: flex-start;: This seems incorrect; it should be min-height or height instead of height: flex-start;.
  2. Container Styles:
    • display: grid;: Sets the container to use the CSS Grid layout.
    • grid-template-columns: repeat(4, 0.2fr);: Defines a grid with four columns of equal width.
    • background: linear-gradient(to right, #00c6fb, #005bea);: Applies a linear gradient background from light blue to dark blue.
    • border-radius: 15px;: Rounds the corners of the container.
    • box-shadow: 0 0 20px rgba(0, 0, 0, 0.2);: Adds a subtle box shadow.
    • padding: 30px;: Adds padding inside the container.
    • text-align: center;: Centers the text within the container.
    • max-width: 700px; width: 100%;: Sets a maximum width for the container and makes it responsive.
    • margin: 10px;: Adds margin around the container.
  3. Form Styles:
    • display: flex; flex-direction: column; gap: 15px;: Styles the form elements as a flex container with a column layout and some spacing between elements.
  4. Label Styles:
    • display: block; margin-top: 15px; color: #000000; font-size: 20px;: Styles labels as block elements with a margin, color, and font size.
  5. Input Styles:
    • width: flex-left;: This is incorrect; it should be width: 100%; to make the input elements fill the available width.
    • Various styling for padding, margin, border, border-radius, outline, text alignment, font size, and transitions.
    • input:hover: Changes the border color and performs a slight upward translation on hover.
  6. Button Styles:
    • display: flex; padding: 10px; margin-bottom: 10px;: Styles buttons as flex containers with padding and margin.
    • Various styling for cursor, background color, text color, font size, border, border-radius, transitions, and box shadow.
    • button:hover: Changes the background color, performs a slight upward translation, and adjusts the box shadow on hover.
    • button:active: Performs a slight downward translation when the button is clicked.
  7. Reset Button Styles:
    • Extends the general button styles and sets a different background color for the reset button.
  8. Result Styles:
    • margin-top: 30px; font-size: 24px; color: #000000;: Styles the result div with margin, font size, and color.

Overall, these styles aim to create a visually appealing and user-friendly interface for the percentage calculator, with a responsive layout and interactive button effects.

function calculateBasicPercentage() {
  let part = parseFloat(document.getElementById('part').value);
  let whole = parseFloat(document.getElementById('whole').value);
  let percentage = (part / whole) * 100;

function calculatePercentageChange() {
  let oldVal = parseFloat(document.getElementById('oldVal').value);
  let newVal = parseFloat(document.getElementById('newVal').value);
  let percentageChange = ((newVal - oldVal) / oldVal) * 100;

function calculateDiscountMarkup() {
  let originalPrice = parseFloat(document.getElementById('part').value);
  let percentage = parseFloat(document.getElementById('percentage').value);
  let finalPrice = originalPrice * (1 + percentage / 100);

function calculatePercentageOfNumber() {
  let percentage = parseFloat(document.getElementById('percentage').value);
  let number = parseFloat(document.getElementById('number').value);
  let result = (percentage / 100) * number;

function calculatePercentageError() {
  let measuredVal = parseFloat(document.getElementById('measuredVal').value);
  let actualVal = parseFloat(document.getElementById('actualVal').value);
  let percentageError = ((measuredVal - actualVal) / actualVal) * 100;

function calculateCompoundInterest() {
  let principal = parseFloat(document.getElementById('part').value);
  let rate = parseFloat(document.getElementById('rate').value);
  let time = parseFloat(document.getElementById('time').value);
  let compoundInterest = principal * Math.pow(1 + rate / 100, time) - principal;

function displayResult(result) {
  document.getElementById('result').innerHTML = `Result: ${result.toFixed(2)}%`;

function resetForm() {
  document.getElementById('result').innerHTML = '';
  document.querySelectorAll('input').forEach(input => input.value = '');

This JavaScript code defines a series of functions for a percentage calculator. Let’s break down each function:

  1. calculateBasicPercentage:
    • Retrieves the values of ‘part’ and ‘whole’ from the input fields in the HTML.
    • Calculates the percentage using the formula: (part / whole) * 100.
    • Calls the displayResult function with the calculated percentage.
  2. calculatePercentageChange:
    • Retrieves the values of ‘oldVal’ and ‘newVal’ from the input fields in the HTML.
    • Calculates the percentage change using the formula: ((newVal - oldVal) / oldVal) * 100.
    • Calls the displayResult function with the calculated percentage change.
  3. calculateDiscountMarkup:
    • Retrieves the values of ‘originalPrice’ and ‘percentage’ from the input fields in the HTML.
    • Calculates the final price after applying a discount or markup using the formula: originalPrice * (1 + percentage / 100).
    • Calls the displayResult function with the calculated final price.
  4. calculatePercentageOfNumber:
    • Retrieves the values of ‘percentage’ and ‘number’ from the input fields in the HTML.
    • Calculates the result, which is a percentage of the given number, using the formula: (percentage / 100) * number.
    • Calls the displayResult function with the calculated result.
  5. calculatePercentageError:
    • Retrieves the values of ‘measuredVal’ and ‘actualVal’ from the input fields in the HTML.
    • Calculates the percentage error using the formula: ((measuredVal - actualVal) / actualVal) * 100.
    • Calls the displayResult function with the calculated percentage error.
  6. calculateCompoundInterest:
    • Retrieves the values of ‘principal’, ‘rate’, and ‘time’ from the input fields in the HTML.
    • Calculates compound interest using the formula: principal * Math.pow(1 + rate / 100, time) - principal.
    • Calls the displayResult function with the calculated compound interest.
  7. displayResult:
    • Takes a result value as an argument.
    • Sets the inner HTML of the ‘result’ div to display the result with formatting: "Result: ${result.toFixed(2)}%".
  8. resetForm:
    • Clears the result display by setting the inner HTML of the ‘result’ div to an empty string.
    • Resets the values of all input fields by iterating through them and setting their values to an empty string.

These functions work together to perform various percentage calculations based on user input and display the results on the web page. The calculations cover basic percentage, percentage change, discount/markup, percentage of a number, percentage error, and compound interest. The resetForm function is provided to reset the form and clear the result.

Steps For Implementation On WordPress:

To implement this Percentage calculator on a WordPress site, follow these steps:

  1. Create a New Page:
    • Log in to your WordPress admin dashboard.
    • Navigate to “Pages” and click “Add New.”
    • Enter a title for your page, e.g., “Age Calculator.”
  2. Switch to HTML Editor:
    • In the WordPress editor, switch to the HTML editor mode.
  3. Copy HTML Content:
    • Copy the entire HTML code along with embedded CSS and JavaScript.
  4. Paste Code:
    • Paste the copied code into the HTML editor of your WordPress page.
  5. Update/Publish:
    • Click the “Update” or “Publish” button to save the changes.
  6. View Page:
    • Visit the page on your WordPress site to see the Age Calculator in action.

Note: Depending on your WordPress theme and plugins, you may encounter styling conflicts. Adjustments might be needed to ensure proper integration.

How does our percent calculator operate?

Our percent calculator operates using intelligent algorithms to accurately determine percentages from input values. It simplifies the often tricky process of manually calculating percentages, considering that not everyone is proficient at solving math equations. The tool is designed to be user-friendly, requiring only the submission of values to swiftly calculate percentages with a single click. No registration hassles – you can use the percent calculator right away.

Why Use Percentage Calculator?

A percentage calculator proves invaluable in various fields for many common scenarios:

  1. Calculate Sales Tax Percentage:
    • Determine the sales tax on purchased items, as it is typically expressed in percentage. Easily find out how much you’ll be paying in taxes for a specific product or service.
  2. Income Percentage Calculator:
    • For those with a fixed income who wish to save a specific percentage, the percent calculator provides an easy solution. Quickly find the amount of income you want to save with accurate results.
  3. Percentage Discount:
    • Use the percentage calculator to calculate discounts when shopping for products on sale. Understand the discounted amount and final price with ease.
  4. Calculate Body Fat Percentage:
    • Maintain your fitness goals by using our online percentage calculator to determine the proportion of fat in your body relative to its weight.
  5. Store Discounts:
    • When encountering store discounts presented in percentages, the percentage calculator helps you understand the final price after applying the discount.
  6. Sales Tax:
    • Easily understand the percentage of sales tax you’re paying for the goods or services you enjoy by utilizing the online percentage calculator.
  7. Interest Rate:
    • Before applying for a loan, check the interest rate and determine the repayable amount against the loan using the free online percentage calculator.
  8. Statistics:
    • Students and statisticians in the field of statistics can benefit from the percentage calculator to enhance their understanding of finding percentages in a straightforward manner.

Q&A for Percentage Calculator

Q1: What is the definition of percentage?

A: Percentage is the ratio of a number expressed as a fraction of 100, typically denoted with the percent symbol, “%.”

Q2: How can I calculate the percentage between two numbers?

A: You can calculate the percentage between two numbers using a percentage calculator. Online tools are available, allowing you to input the two numbers and obtain the percentage result quickly.

Q3: What calculations can be performed with a percentage converter?

A: A percentage converter enables various calculations, such as determining the ratio of a student’s marks or assessing the amount paid in taxes. It’s a versatile tool for accurate percentage-related computations.

Q4: Can a percentage exceed 100?

A: No, when identifying the percentage of a number, it cannot exceed 100. However, in percentage differences between two values, the result can be greater than 100.

Q5: Can a percentage be negative?

A: No, the percentage of a number itself cannot be negative. Negative percentages may arise when finding the percentage difference between two values, but the negative sign is typically ignored, and the percentage is expressed in positive integers.

Q6: Can a percentage be represented as a decimal?

A: No, a percentage cannot be a decimal directly because it is obtained by multiplying the decimal value by 100.

Q7: Is it possible to calculate percentage without a percent calculator?

A: Yes, you can calculate percentage using the percentage calculation formula without an online calculator. However, for complex values, independent calculation may require additional assistance.

Q8: How is percentage calculated?

A: Percentage is calculated by taking the ratio of a number to 100 and expressing it as a fraction. The formula is (part/whole) * 100.

Q9: Can you provide an example of calculating percentage without a calculator?

A: Certainly, for simple cases, you can use the formula. For example, if you scored 75 out of 100, the percentage would be (75/100) * 100 = 75%.

Q10: What does the percent symbol, “%,” signify in percentage calculations?

A: The percent symbol signifies that the number is being expressed as a portion of 100, making it easier to understand and compare.

Q11: Why is it important to consider ignoring the negative sign in certain percentage calculations?

A: In certain contexts, like percentage differences, negative values may arise. Ignoring the negative sign ensures that the percentage is expressed in positive integers for clarity.

Q12: Can you provide an instance where a percentage difference might result in a value greater than 100?

A: Yes, in scenarios where comparing two values with a significant difference, the percentage difference might exceed 100, indicating a substantial change between the two values.