Calorie Calculator

Adjust Distance Between Inputs

Calorie Calculator

About This calculator

A Calorie Calculator is a tool designed to estimate the number of calories an individual needs to maintain, gain, or lose weight based on various factors such as age, gender, weight, height, body fat percentage, and activity level. The calculation is usually based on formulas that take into account the energy expenditure associated with basic bodily functions (Basal Metabolic Rate or BMR) and physical activity.

Here are some key components and concepts often involved in a Calorie Calculator:

  1. Basal Metabolic Rate (BMR): BMR represents the number of calories your body needs to maintain basic physiological functions while at rest. It’s the energy expended to maintain vital processes like breathing, circulation, and cell production.
  2. Activity Level: Different levels of physical activity contribute to overall energy expenditure. Common activity levels include sedentary (little or no exercise), light exercise, moderate exercise, active, very active, and extra active.
  3. Total Daily Energy Expenditure (TDEE): TDEE is the total number of calories your body needs in a day, considering both BMR and the calories burned through physical activity.
  4. Formulas: There are several formulas used to estimate BMR and TDEE. Common ones include the Mifflin-St Jeor equation, the Harris-Benedict equation, and the Katch-McArdle formula. These formulas consider factors like gender, age, weight, height, and, in some cases, body fat percentage.
  5. Unit Systems: Calorie calculators often allow users to choose between different unit systems, such as Imperial/US units (pounds, inches, etc.) and Metric units (kilograms, centimeters, etc.).
  6. Body Fat Percentage: Some calculators take into account body fat percentage, as muscle mass can affect calorie needs.

How To Use This Calculator ?

  1. Select Unit System:
    • Use the dropdown menu labeled “Select Unit System” to choose between “Imperial/US” and “Metric.”
  2. Provide Personal Information:
    • Fill in the required information based on the selected unit system:
      • Gender: Choose “Male” or “Female.”
      • Age: Enter your age in years.
      • Height: Enter your height in either inches or centimeters, depending on the unit system.
      • Weight: Enter your weight in either pounds or kilograms, depending on the unit system.
      • Body Fat Percentage: Enter your body fat percentage (if known).
      • Activity Level: Choose your activity level from the options provided.
  3. Click “Calculate Calories”:
    • After entering your information, click the “Calculate Calories” button.
  4. View Results:
    • The tool will calculate and display the estimated daily calorie requirements based on the provided information.
    • The result includes the total calories in kilocalories (kcal) and kilojoules (kJ).
  5. Explore Different Scenarios:
    • Experiment with different values for each parameter to see how they affect the calculated calorie needs.
    • Change the unit system, gender, age, height, weight, body fat percentage, and activity level to observe variations in the results.
  6. Readjust as Needed:
    • If you’re using the tool for specific fitness goals, you may want to adjust your parameters accordingly and recalculate.

Examples To Try

Examples for Imperial/US Unit System:

  1. Male, Age 25, Height 72 inches, Weight 185 pounds, Body Fat 18%, Active
  2. Female, Age 30, Height 65 inches, Weight 150 pounds, Body Fat 20%, Moderate Exercise
  3. Male, Age 40, Height 68 inches, Weight 200 pounds, Body Fat 15%, Very Active
  4. Female, Age 35, Height 60 inches, Weight 130 pounds, Body Fat 25%, Light Exercise
  5. Male, Age 28, Height 75 inches, Weight 210 pounds, Body Fat 12%, BMR (no exercise)

Examples for Metric Unit System:

  1. Male, Age 27, Height 180 cm, Weight 80 kg, Body Fat 22%, Active
  2. Female, Age 32, Height 160 cm, Weight 65 kg, Body Fat 18%, Moderate Exercise
  3. Male, Age 45, Height 175 cm, Weight 90 kg, Body Fat 20%, Very Active
  4. Female, Age 38, Height 155 cm, Weight 55 kg, Body Fat 30%, Light Exercise
  5. Male, Age 30, Height 190 cm, Weight 100 kg, Body Fat 10%, BMR (no exercise)

Varied Scenarios:

  1. Male, Age 22, Height 70 inches, Weight 170 pounds, Body Fat 8%, Extra Active
  2. Female, Age 33, Height 62 inches, Weight 140 pounds, Body Fat 22%, Sedentary
  3. Male, Age 37, Height 74 inches, Weight 220 pounds, Body Fat 25%, Active
  4. Female, Age 28, Height 68 inches, Weight 160 pounds, Body Fat 15%, Very Active
  5. Male, Age 31, Height 71 inches, Weight 190 pounds, Body Fat 18%, Moderate Exercise

Specialized Scenarios:

  1. Male Athlete, Age 25, Height 75 inches, Weight 200 pounds, Body Fat 10%, Very Active
  2. Female Bodybuilder, Age 28, Height 68 inches, Weight 150 pounds, Body Fat 12%, Active
  3. Male, Age 60, Height 66 inches, Weight 180 pounds, Body Fat 20%, Light Exercise
  4. Female, Age 45, Height 63 inches, Weight 140 pounds, Body Fat 25%, Extra Active
  5. Male, Age 55, Height 72 inches, Weight 250 pounds, Body Fat 30%, Sedentary

How This Calculator Function ?

HTML Structure:

  • <head> Section:
    • Includes meta tags for character set and viewport settings.
    • Sets the title of the web page.
  • <body> Section:
    • Contains a <div> element with the id “calculator” that wraps the entire content.
  • Calculator Content:
    • Heading (<h2>): Displays “Calorie Calculator” as the title.
    • Unit System Selector (<select>): Allows users to choose between Imperial/US and Metric units.
    • Input Groups (<div class="input-group">): Sections for different input categories (Gender, Age, Height, Weight, Body Fat, Activity Level).
    • Inputs and Labels (<label>, <input>, <select>): Collect user input for various parameters.
    • Calculate Button (<button>): Initiates the calorie calculation when clicked.
    • Result Display (<div id="result">): Displays the calculated calories and energy in kilocalories and kilojoules.

CSS Styling:

  • Global Styles (body):
    • Sets a basic font, removes default margin and padding, and provides a light gray background.
  • Calculator Styles (#calculator):
    • Sets the max width, adds padding, background color using a linear gradient, adds a box shadow, and applies border-radius for a rounded appearance.
  • Input Group Styles (.input-group):
    • Adds a border-radius, margin, and flex styling to arrange labels and inputs in each group.
  • Input and Label Styles (.input-group label, .input-group input, .input-group select):
    • Sets border-radius, width, and box-sizing for consistent styling of inputs and labels.
  • Button Styles (button):
    • Provides styling for the “Calculate Calories” button, including background color, text color, padding, border, border-radius, and cursor style.
  • Result Display Styles (#result):
    • Sets margin-top and font-weight for result presentation.

JavaScript Functionality:

  • updateUnitSystem() Function:
    • Adjusts labels and placeholders based on the selected unit system.
  • calculateCalories() Function:
    • Reads input values, calculates BMR using the Mifflin-St Jeor equation, adjusts BMR based on activity level, and displays the result.

Where This Calculator Can Be Used ?

  1. Nutritional Planning:
    • Individuals looking to manage their weight or achieve specific fitness goals can use the calculator to estimate their daily calorie needs. This information is valuable for creating a balanced and sustainable nutrition plan.
  2. Weight Management:
    • People aiming to lose, maintain, or gain weight can use the calculator to determine an appropriate calorie intake based on their personal factors and activity level.
  3. Fitness Programs:
    • Fitness enthusiasts and athletes can use the calculator to tailor their nutritional intake to support their training and performance goals, ensuring they meet their energy requirements.
  4. Health and Wellness:
    • Individuals focused on maintaining overall health and well-being can use the calculator to understand their calorie needs and make informed decisions about their diet and lifestyle.
  5. Personalized Diet Plans:
    • Nutritionists and dietitians can utilize such calculators to create personalized diet plans for their clients, taking into account individual differences in age, gender, weight, height, and activity level.
  6. Educational Tools:
    • Educational institutions, fitness trainers, and health professionals can use calorie calculators as educational tools to teach individuals about the relationship between calories, nutrition, and physical activity.
  7. Online Health and Fitness Platforms:
    • Calorie calculators are commonly integrated into online platforms, mobile apps, or websites dedicated to health and fitness. Users can access these tools for convenient and quick assessments.
  8. Corporate Wellness Programs:
    • Companies implementing wellness programs for their employees can include calorie calculators as part of the resources provided to promote healthy lifestyle choices.
  9. Medical Rehabilitation:
    • In certain medical contexts, healthcare professionals might use calorie calculators to estimate energy needs for patients undergoing rehabilitation or recovering from illness.
  10. General Awareness:
    • It can serve as a general awareness tool, helping individuals understand the energy requirements associated with their daily activities and the importance of maintaining a balanced diet.
<!DOCTYPE html>
<html lang="en">
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Adjust Distance Between Inputs</title>
  <link rel="stylesheet" type="text/css" href="styles.css">

<div id="calculator">
  <h2>Calorie Calculator</h2>
  <label for="unitSystem">Select Unit System:</label>
  <select id="unitSystem" onchange="updateUnitSystem()">
    <option value="imperial">Imperial/US</option>
    <option value="metric">Metric</option>

  <div class="input-group">
    <label for="gender">Gender:</label>
    <select id="gender">
      <option value="male">Male</option>
      <option value="female">Female</option>
    <label for="age">Age (years):</label>
    <input type="number" id="age" placeholder="Enter your age">

  <div class="input-group">
    <label for="height">Height:</label>
    <input type="number" id="height" placeholder="Enter your height">
    <label for="weight">Weight:</label>
    <input type="number" id="weight" placeholder="Enter your weight">

  <div class="input-group">
    <label for="bodyFat">Body Fat Percentage:</label>
    <input type="number" id="bodyFat" placeholder="Enter your body fat percentage">
    <label for="activityLevel">Activity Level:</label>
    <select id="activityLevel">
      <option value="noExercise">BMR (no exercise)</option>
      <option value="light">Light exercise</option>
      <option value="moderate">Moderate exercise</option>
      <option value="active">Active</option>
      <option value="veryActive">Very active</option>

  <button onclick="calculateCalories()">Calculate Calories</button>

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

<script src="script.js"></script>
  • DOCTYPE Declaration: Specifies the HTML version being used.
  • <html>: The root element of an HTML document.
  • <head>: Contains meta-information about the HTML document.
  • <meta charset="UTF-8">: Sets the character set for the document to UTF-8.
  • <meta name="viewport" content="width=device-width, initial-scale=1.0">: Configures the viewport settings for responsive design.
  • <title>: Sets the title of the HTML document.
  • <link rel="stylesheet" type="text/css" href="styles.css">: Links the external CSS file.
  • <body>: Contains the content of the HTML document.
  • <div id="calculator">: A container for the entire calculator content.
  • <h2>: Heading indicating the purpose of the calculator.
  • <label>: Labels for various input fields.
  • <select>: Dropdown menus for selecting options.
  • <input type="number">: Input fields for numeric values.
  • <button onclick="calculateCalories()">: Button to trigger the calculation.
  • <div id="result">: Container for displaying the calculation result.
  • <script src="script.js"></script>: Links the external JavaScript file.
/* Your styles here */
body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background-color: #f4f4f4;

#calculator {
  margin: 20px;
  max-width: 600px;
  margin: 0px auto;
  padding: 20px;
  background: linear-gradient(to right, #3498db, #2ecc71);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
  color: #fff;

.input-group {
  border-radius: 20px;
  margin: 10px;
  display: flex;
  justify-content: space-between;
  margin-bottom: 16px;

.input-group label,
.input-group input,
.input-group select {
  border-radius: 10px;
  width: 48%; /* Adjust this value based on your preference */
  box-sizing: border-box;

label {
  display: block;
  margin-bottom: 8px;

input, select {
  width: 100%;
  padding: 8px;
  box-sizing: border-box;

button {
  background-color: #fff;
  color: #3498db;
  padding: 10px 15px;
  border: none;
  border-radius: 4px;
  cursor: pointer;

#result {
  margin-top: 20px;
  font-weight: bold;
  • body: Sets styles for the entire document.
  • #calculator: Styles for the main calculator container.
  • .input-group: Styles for the container of each group of inputs.
  • .input-group label, .input-group input, .input-group select: Styles for labels, inputs, and selects within an input group.
  • button: Styles for the calculate button.
  • #result: Styles for the result display.
function updateUnitSystem() {
  const unitSystem = document.getElementById("unitSystem").value;

  // Adjust labels based on unit system
  document.querySelector('label[for="height"]').textContent = (unitSystem === 'imperial') ? 'Height (inches):' : 'Height (cm):';
  document.querySelector('label[for="weight"]').textContent = (unitSystem === 'imperial') ? 'Weight (pounds):' : 'Weight (kg):';

  // Adjust placeholder text
  document.getElementById("height").placeholder = (unitSystem === 'imperial') ? 'Enter your height in inches' : 'Enter your height in cm';
  document.getElementById("weight").placeholder = (unitSystem === 'imperial') ? 'Enter your weight in pounds' : 'Enter your weight in kg';

function calculateCalories() {
  const unitSystem = document.getElementById("unitSystem").value;
  const gender = document.getElementById("gender").value;
  const age = parseFloat(document.getElementById("age").value);
  const height = parseFloat(document.getElementById("height").value);
  const weight = parseFloat(document.getElementById("weight").value);
  const bodyFat = parseFloat(document.getElementById("bodyFat").value);
  const activityLevel = parseFloat(document.getElementById("activityLevel").value);

  // Adjust formulas based on unit system
  const heightMultiplier = (unitSystem === 'imperial') ? 1 : 2.54;
  const weightMultiplier = (unitSystem === 'imperial') ? 1 : 0.453592;

  // Calculate BMR using Mifflin-St Jeor equation
  let bmr;
  if (gender === "male") {
    bmr = 10 * (weight * weightMultiplier) + 6.25 * (height * heightMultiplier) - 5 * age + 5;
  } else {
    bmr = 10 * (weight * weightMultiplier) + 6.25 * (height * heightMultiplier) - 5 * age - 161;

  // Adjust BMR based on activity level
  let tdee;
  switch (activityLevel) {
    case 1.2:
      tdee = bmr * 1.2;
    case 1.375:
      tdee = bmr * 1.375;
    case 1.55:
      tdee = bmr * 1.55;
    case 1.725:
      tdee = bmr * 1.725;
    case 1.9:
      tdee = bmr * 1.9;
      tdee = bmr; // Default to BMR (no exercise)

  // Display result
  const resultElement = document.getElementById("result");
  resultElement.textContent = "Calories: " + tdee.toFixed(2) + " kcal (" + (tdee * 4.184).toFixed(2) + " kJ)";
  • updateUnitSystem(): Function to update labels and placeholders based on the selected unit system.
  • calculateCalories(): Function to perform the calorie calculation based on user input.
  • document.getElementById(): Retrieves an HTML element by its ID.
  • document.querySelector(): Retrieves the first element that matches a specified CSS selector.
  • parseFloat(): Parses a string and returns a floating-point number.
  • switch statement: Evaluates an expression, matching the expression’s value to a case clause, and executes the statements associated with that case.
  • toFixed(): Rounds a number to a specified number of decimal places.
  • Manipulation of HTML content and styles: Updating text content, adjusting placeholders, and modifying styles dynamically based on user input.

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 Calorie Calculator?
    • A: A Calorie Calculator is a tool that estimates the number of calories a person needs to consume daily based on factors like age, gender, weight, height, body fat percentage, and activity level.
  2. Q: Why is it important to calculate daily calorie needs?
    • A: Calculating daily calorie needs helps individuals maintain a balanced diet, manage weight, and achieve fitness goals by ensuring they consume an appropriate amount of calories.
  3. Q: How does a Calorie Calculator work?
    • A: Calorie Calculators use mathematical formulas, often based on factors like Basal Metabolic Rate (BMR) and activity level, to estimate the number of calories needed for daily energy expenditure.
  4. Q: What is BMR, and how does it factor into calorie calculations?
    • A: BMR (Basal Metabolic Rate) represents the number of calories the body needs at rest. Calorie Calculators often use BMR as a starting point and adjust it based on activity level.
  5. Q: What are the common units used in Calorie Calculators?
    • A: Common units include pounds and kilograms for weight, inches and centimeters for height, and calories for energy.
  6. Q: What are the different activity levels used in Calorie Calculators?
    • A: Activity levels typically range from sedentary (no exercise) to very active, with variations like light exercise, moderate exercise, and active.
  7. Q: Can a Calorie Calculator help with weight loss?
    • A: Yes, Calorie Calculators can be used to set calorie intake goals for weight loss by creating a calorie deficit.
  8. Q: How accurate are Calorie Calculators?
    • A: While Calorie Calculators provide estimates, individual variations and factors can affect accuracy. They serve as useful guidelines but may not be precise for everyone.
  9. Q: What is the difference between Caloric Intake and Caloric Expenditure?
    • A: Caloric Intake is the number of calories consumed through food, while Caloric Expenditure is the number of calories the body burns through various activities.
  10. Q: Can a Calorie Calculator help with muscle gain?
  • A: Yes, Calorie Calculators can help individuals determine the appropriate calorie surplus for muscle gain when combined with resistance training.
  1. Q: How often should I recalculate my daily calorie needs?
  • A: Recalculating may be necessary when there are significant changes in weight, activity level, or body composition.
  1. Q: Are there specific Calorie Calculators for certain diets, like keto or vegan?
  • A: Some calculators may consider dietary preferences, but the primary focus is usually on overall calorie balance.
  1. Q: Can age influence calorie needs?
  • A: Yes, age is a factor in calorie calculations. BMR tends to decrease with age, affecting overall calorie requirements.
  1. Q: How can body fat percentage affect calorie calculations?
  • A: Body fat percentage can influence calorie needs, as individuals with a higher percentage may have different metabolic rates.
  1. Q: Is there a difference between calorie and kilojoule calculations?
  • A: Yes, calorie calculators may provide results in both calories and kilojoules. One calorie is approximately equal to 4.184 kilojoules.
  1. Q: Can a Calorie Calculator be used for maintenance after reaching a fitness goal?
  • A: Yes, recalibrating calorie needs for maintenance is essential once fitness goals are achieved.
  1. Q: Are there specific Calorie Calculators for medical conditions?
  • A: Some calculators may consider medical conditions, but it’s important to consult with healthcare professionals for personalized advice.
  1. Q: How can I track calories for more accurate results?
  • A: Keeping a food diary and using apps can help track calorie intake, providing more accurate data for calculations.
  1. Q: Can a Calorie Calculator help with creating a balanced diet plan?
  • A: Yes, by determining the appropriate calorie distribution among macronutrients, Calorie Calculators can aid in creating a balanced diet.
  1. Q: Are there mobile apps with built-in Calorie Calculators?
  • A: Yes, many health and fitness apps offer Calorie Calculators, making it convenient for users to track and manage their nutrition on the go.