Calorie Expenditure Calculator

Calorie Expenditure Calculator

Estimate your daily calorie needs based on your basal metabolic rate (BMR) and activity level.

Sedentary (little or no exercise) Lightly active (light exercise/sports 1-3 days/week) Moderately active (moderate exercise/sports 3-5 days/week) Very active (hard exercise/sports 6-7 days a week) Extra active (very hard exercise/physical job)

function calculateCalorieExpenditure() { var age = parseFloat(document.getElementById('age').value); var gender = document.querySelector('input[name="gender"]:checked').value; var weight = parseFloat(document.getElementById('weight').value); var height = parseFloat(document.getElementById('height').value); var activityFactor = parseFloat(document.getElementById('activityLevel').value); var resultDiv = document.getElementById('calorieExpenditureResult'); resultDiv.innerHTML = "; // Clear previous results // Input validation if (isNaN(age) || age <= 0 || isNaN(weight) || weight <= 0 || isNaN(height) || height <= 0) { resultDiv.innerHTML = 'Please enter valid positive numbers for age, weight, and height.'; return; } var bmr; // Basal Metabolic Rate // Mifflin-St Jeor Equation if (gender === 'male') { bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { // female bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } var tdee = bmr * activityFactor; // Total Daily Energy Expenditure resultDiv.innerHTML = '

Your Estimated Calorie Expenditure:

' + 'Basal Metabolic Rate (BMR): ' + bmr.toFixed(0) + ' calories/day' + 'Total Daily Energy Expenditure (TDEE): ' + tdee.toFixed(0) + ' calories/day' + 'Your BMR is the number of calories your body burns at rest. Your TDEE includes calories burned through daily activities and exercise.'; } .calorie-expenditure-calculator { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: #f9f9f9; padding: 25px; border-radius: 10px; box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1); max-width: 600px; margin: 20px auto; color: #333; } .calorie-expenditure-calculator h2 { color: #2c3e50; text-align: center; margin-bottom: 20px; font-size: 1.8em; } .calorie-expenditure-calculator p { line-height: 1.6; margin-bottom: 15px; } .calorie-expenditure-calculator .calculator-form label { display: block; margin-bottom: 8px; font-weight: bold; color: #555; } .calorie-expenditure-calculator .calculator-form input[type="number"], .calorie-expenditure-calculator .calculator-form select { width: calc(100% – 20px); padding: 12px; margin-bottom: 15px; border: 1px solid #ccc; border-radius: 5px; font-size: 1em; box-sizing: border-box; } .calorie-expenditure-calculator .gender-options { margin-bottom: 15px; display: flex; gap: 15px; align-items: center; } .calorie-expenditure-calculator .gender-options input[type="radio"] { margin-right: 5px; width: auto; } .calorie-expenditure-calculator .gender-options label { margin-bottom: 0; font-weight: normal; } .calorie-expenditure-calculator button { background-color: #28a745; color: white; padding: 12px 25px; border: none; border-radius: 5px; cursor: pointer; font-size: 1.1em; display: block; width: 100%; margin-top: 20px; transition: background-color 0.3s ease; } .calorie-expenditure-calculator button:hover { background-color: #218838; } .calorie-expenditure-calculator .calculator-result { background-color: #e9f7ef; border: 1px solid #d4edda; padding: 15px; border-radius: 8px; margin-top: 25px; font-size: 1.1em; color: #155724; } .calorie-expenditure-calculator .calculator-result h3 { color: #218838; margin-top: 0; margin-bottom: 10px; font-size: 1.4em; } .calorie-expenditure-calculator .calculator-result p { margin-bottom: 8px; } .calorie-expenditure-calculator .calculator-result p strong { color: #0f5132; }

Understanding Your Calorie Expenditure

Calorie expenditure refers to the total number of calories your body burns in a day. This energy is used for everything from basic bodily functions to physical activity. Understanding your daily calorie expenditure is crucial for managing your weight, whether you're looking to lose, gain, or maintain it.

How Your Body Burns Calories

Your total daily calorie expenditure is primarily made up of three components:

1. Basal Metabolic Rate (BMR): This is the number of calories your body burns at rest to maintain vital functions like breathing, circulation, body temperature, and cell production. It accounts for the largest portion of your daily calorie burn (60-75%).
2. Thermic Effect of Food (TEF): This is the energy your body uses to digest, absorb, and metabolize the food you eat. It typically accounts for about 10% of your total calorie expenditure.
3. Activity Energy Expenditure (AEE): This includes all calories burned through physical activity, from structured exercise to non-exercise activity thermogenesis (NEAT) like walking, fidgeting, and standing. This component is the most variable.

How Our Calculator Works

Our Calorie Expenditure Calculator uses the widely recognized Mifflin-St Jeor Equation to estimate your Basal Metabolic Rate (BMR). This formula is considered one of the most accurate for predicting BMR:

• For Men: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
• For Women: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161

Once your BMR is calculated, we multiply it by an activity factor to determine your Total Daily Energy Expenditure (TDEE). This factor accounts for your typical physical activity level:

• Sedentary (1.2): Little or no exercise, desk job.
• Lightly Active (1.375): Light exercise/sports 1-3 days/week.
• Moderately Active (1.55): Moderate exercise/sports 3-5 days/week.
• Very Active (1.725): Hard exercise/sports 6-7 days a week.
• Extra Active (1.9): Very hard exercise, physical job, or training twice a day.

Example Calculation

Let's consider an example:

• Age: 30 years
• Gender: Female
• Weight: 65 kg
• Height: 170 cm
• Activity Level: Moderately active (factor 1.55)

First, calculate BMR for a female:

BMR = (10 × 65) + (6.25 × 170) – (5 × 30) – 161

BMR = 650 + 1062.5 – 150 – 161

BMR = 1401.5 calories/day

Next, calculate TDEE:

TDEE = BMR × Activity Factor

TDEE = 1401.5 × 1.55

TDEE = 2172.325 calories/day

So, this individual would expend approximately 1402 calories at rest and a total of about 2172 calories per day with a moderately active lifestyle.

Why is this important for you?

• Weight Loss: To lose weight, you need to consume fewer calories than you expend (create a calorie deficit).
• Weight Gain: To gain weight, you need to consume more calories than you expend (create a calorie surplus).
• Weight Maintenance: To maintain your current weight, you should aim to consume roughly the same number of calories as you expend.

While this calculator provides a good estimate, individual metabolic rates can vary. Factors like body composition (muscle vs. fat), genetics, and certain medical conditions can influence your actual calorie expenditure. For personalized advice, always consult with a healthcare professional or a registered dietitian.