Calorie Calculator

Calorie Calculator - Free Online BMR and TDEE Calculator

Calculate your daily calorie needs with our free online Calorie Calculator. This tool uses the widely respected Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR) and then applies your activity level to determine your Total Daily Energy Expenditure (TDEE). Whether your goal is to lose weight, maintain your current weight, or build muscle, knowing your daily calorie requirements is the essential first step.

Understanding how many calories your body burns each day helps you make informed decisions about nutrition and fitness. This calculator provides personalized estimates based on your gender, age, height, weight, and activity level, along with helpful targets for weight loss and weight gain.

How to Use

1. Select your gender from the dropdown menu.
2. Enter your age in years.
3. Enter your height in centimeters (e.g., 175 cm).
4. Enter your weight in kilograms (e.g., 70 kg).
5. Choose the activity level that best describes your typical week, from sedentary (no exercise) to extra active (intense exercise twice daily).
6. Click "Calculate" to see your BMR, TDEE, and suggested calorie targets for weight loss and weight gain.

Understanding BMR and TDEE

• BMR (Basal Metabolic Rate): The number of calories your body needs to perform basic life-sustaining functions like breathing, circulation, cell production, and nutrient processing while completely at rest. Even if you stayed in bed all day, your body would still burn this many calories.
• TDEE (Total Daily Energy Expenditure): Your BMR multiplied by an activity factor that accounts for all the calories you burn through physical movement, exercise, and the thermic effect of food. This number represents the total calories you burn in a typical day.
• Activity Multipliers: Sedentary (1.2), Lightly active (1.375), Moderately active (1.55), Very active (1.725), Extra active (1.9). Choosing the correct activity level is important for an accurate estimate.

The Mifflin-St Jeor Equation

This calculator uses the Mifflin-St Jeor equation, which research has shown to be the most accurate predictive equation for estimating BMR in most individuals. The formulas are: for men, BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) + 5; for women, BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) - 161. The result is then multiplied by the activity factor to calculate TDEE.

Frequently Asked Questions

Q. How many calories should I eat to lose weight?

A. A moderate calorie deficit of 300 to 500 calories below your TDEE is generally recommended for healthy, sustainable weight loss. This typically results in losing about 0.3 to 0.5 kg (0.7 to 1.1 lbs) per week. Avoid going below your BMR, as eating too few calories can slow your metabolism, cause muscle loss, and lead to nutritional deficiencies. Always consult a healthcare professional before starting a significant calorie restriction.

Q. How accurate is this calorie calculator?

A. The Mifflin-St Jeor equation provides a reliable estimate for most people, but individual results can vary by 5-10%. Factors like genetics, muscle mass, hormonal conditions, and medications can affect your actual metabolic rate. Use the calculated TDEE as a starting point and adjust based on your real-world results over 2-4 weeks. If you are gaining or losing weight unexpectedly, adjust your calorie intake accordingly.

Q. Should I eat back the calories I burn during exercise?

A. Your TDEE already accounts for exercise calories based on the activity level you selected. If you selected "moderately active" and you typically exercise 3-5 days per week, those exercise calories are already included in your TDEE estimate. You do not need to add extra calories on workout days unless your exercise was significantly more intense than your usual routine. For very long or intense workouts, a small additional snack may be appropriate.