Calories Expenditure Calculator

Daily Calorie Expenditure Calculator

Estimate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) to understand your body's calorie needs.

function calculateCalorieExpenditure() { var genderMale = document.getElementById("genderMale").checked; var genderFemale = document.getElementById("genderFemale").checked; var age = parseFloat(document.getElementById("age").value); var weight = parseFloat(document.getElementById("weight").value); var height = parseFloat(document.getElementById("height").value); var activityLevel = parseFloat(document.getElementById("activityLevel").value); // Input validation if (isNaN(age) || age <= 0 || isNaN(weight) || weight <= 0 || isNaN(height) || height <= 0) { document.getElementById("bmrResult").textContent = "Please enter valid positive numbers for all fields."; document.getElementById("tdeeResult").textContent = "N/A"; return; } var bmr; // Mifflin-St Jeor Equation if (genderMale) { bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else if (genderFemale) { bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } else { document.getElementById("bmrResult").textContent = "Please select a gender."; document.getElementById("tdeeResult").textContent = "N/A"; return; } var tdee = bmr * activityLevel; document.getElementById("bmrResult").textContent = bmr.toFixed(0); document.getElementById("tdeeResult").textContent = tdee.toFixed(0); }

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 intense physical activity. Understanding your daily calorie expenditure is a fundamental step in managing your weight, whether you aim to lose, maintain, or gain weight.

What is Basal Metabolic Rate (BMR)?

Your Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic, life-sustaining functions while at rest. This includes breathing, circulation, cell production, nutrient processing, and maintaining body temperature. It's the energy your body would burn if you were to lie in bed all day doing nothing. BMR accounts for a significant portion (typically 60-75%) of your total daily calorie expenditure.

The calculator above uses the Mifflin-St Jeor equation, which is widely considered one of the most accurate formulas for estimating 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

What is Total Daily Energy Expenditure (TDEE)?

While BMR tells you how many calories you burn at rest, your Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a 24-hour period, taking into account your physical activity level. TDEE includes your BMR, the calories burned during physical activity, and the thermic effect of food (TEF), which is the energy used to digest, absorb, and metabolize food.

TDEE is calculated by multiplying your BMR by an activity factor, which varies based on how active you are:

• Sedentary (little or no exercise): BMR × 1.2
• Lightly active (light exercise/sports 1-3 days/week): BMR × 1.375
• Moderately active (moderate exercise/sports 3-5 days/week): BMR × 1.55
• Very active (hard exercise/sports 6-7 days a week): BMR × 1.725
• Extremely active (very hard exercise/physical job): BMR × 1.9

How to Use the Calculator

To use the calculator, simply input your gender, age, weight in kilograms, height in centimeters, and select your typical activity level from the dropdown menu. The calculator will then provide you with your estimated BMR and TDEE.

Example Calculation:

Let's consider a 30-year-old female who is 165 cm tall and weighs 60 kg, with a moderately active lifestyle.

1. Calculate BMR (Female):
   (10 × 60 kg) + (6.25 × 165 cm) – (5 × 30 years) – 161
   = 600 + 1031.25 – 150 – 161
   = 1320.25 calories
2. Calculate TDEE (Moderately Active):
   1320.25 calories (BMR) × 1.55 (Activity Factor)
   = 2046.39 calories

This individual would have an estimated BMR of approximately 1320 calories and a TDEE of about 2046 calories per day.

For a 35-year-old male who is 180 cm tall and weighs 80 kg, with a lightly active lifestyle:

1. Calculate BMR (Male):
   (10 × 80 kg) + (6.25 × 180 cm) – (5 × 35 years) + 5
   = 800 + 1125 – 175 + 5
   = 1755 calories
2. Calculate TDEE (Lightly Active):
   1755 calories (BMR) × 1.375 (Activity Factor)
   = 2413.13 calories

This individual would have an estimated BMR of approximately 1755 calories and a TDEE of about 2413 calories per day.

Why is This Important for Weight Management?

Knowing your TDEE is crucial for setting realistic goals:

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

Remember that these calculations are estimates. Individual metabolic rates can vary, and factors like body composition (muscle vs. fat), genetics, and certain health conditions can influence your actual calorie expenditure. For personalized advice, always consult with a healthcare professional or a registered dietitian.