Whether your goal is to lose fat, build muscle, or simply maintain your current weight, understanding your body's energy needs is the first step. Your Total Daily Energy Expenditure (TDEE) is the most important number in nutrition—it's the total amount of calories your body burns in a 24-hour period. Knowing this number is the key to creating an effective and personalized eating plan.
This calculator uses the Mifflin-St Jeor equation, one of the most accurate methods for estimating your baseline metabolism, to determine your TDEE.
How to Use the TDEE Calculator
To calculate your TDEE, the tool first determines your Basal Metabolic Rate (BMR) and then multiplies it by your activity level. Please provide the following:
- Your Biometrics: Enter your age, sex, height, and current weight.
- Your Activity Level: Be honest about your weekly activity. Most people who work desk jobs fall into the 'Lightly Active' or 'Moderately Active' categories. Choose the option that best describes your typical week.
The calculator will provide you with a single, powerful number: your estimated daily TDEE, which is also your 'maintenance calorie' target.
The Components of Your TDEE
Your TDEE isn't just about your workout. It's made up of four key components:
- Basal Metabolic Rate (BMR): This is the energy your body burns at complete rest to keep your organs functioning. It's the largest part of your TDEE.
- Thermic Effect of Food (TEF): The calories your body uses to digest, absorb, and process the food you eat.
- Exercise Activity Thermogenesis (EAT): The calories you burn during intentional, planned exercise like running, weightlifting, or a fitness class.
- Non-Exercise Activity Thermogenesis (NEAT): All the other calories you burn from daily movements, such as walking, fidgeting, doing chores, and even typing. This is the most variable component of TDEE.
Using Your TDEE to Achieve Your Goals
Once you know your TDEE, you can adjust your daily calorie intake to match your goals:
- For Fat Loss: To lose weight, you need to be in a calorie deficit. A sustainable starting point is to consume 300-500 calories *less* than your TDEE per day.
- For Muscle Gain: To build muscle, you need to be in a calorie surplus to fuel growth. A modest surplus of 200-300 calories *more* than your TDEE, combined with a solid resistance training program, is a great starting point.
- For Weight Maintenance: To maintain your current weight, simply aim to eat at or around your calculated TDEE.
Important Medical Notes
This calculator provides a scientific estimate of your energy needs, but it is not an absolute rule. Individual factors like genetics, body composition (muscle vs. fat), and hormonal health can influence your actual TDEE. Use this number as a starting point, monitor your results, and adjust as needed. For personalized nutrition advice, please consult with a registered dietitian or your doctor.