How Many Calories Should You Eat? A Guide to TDEE

Whether you want to lose weight, gain muscle, or maintain your current physique, the most important number to know is your Total Daily Energy Expenditure (TDEE). This is the number of calories your body burns each day, and it is the foundation of any effective nutrition plan. In this guide, we explain how TDEE is calculated, what BMR means, and how to use Calnivo's free Calorie Calculator to reach your goals.

What Is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to stay alive. Even if you slept all day, your body would still burn calories to maintain breathing, circulation, cell production, and brain function. BMR accounts for approximately 60-70% of your total daily calorie burn.

Several formulas exist for estimating BMR. The most widely used is the Mifflin-St Jeor equation, published in 1990:

Men: BMR = 10 × W + 6.25 × H − 5 × A + 5
Women: BMR = 10 × W + 6.25 × H − 5 × A − 161

Where:

• W = Weight in kilograms
• H = Height in centimeters
• A = Age in years

For example, a 30-year-old male weighing 75 kg and 175 cm tall would have a BMR of: 10 × 75 + 6.25 × 175 − 5 × 30 + 5 = 750 + 1093.75 − 150 + 5 = 1,698.75 calories per day.

What Is TDEE?

Total Daily Energy Expenditure (TDEE) is your BMR multiplied by an activity factor that accounts for your daily movement and exercise. The standard activity multipliers are:

Using our example male with a BMR of 1,698.75 and a moderately active lifestyle (multiplier 1.55): TDEE = 1,698.75 × 1.55 = 2,633 calories per day.

How to Use TDEE for Your Goals

Once you know your TDEE, you can adjust your calorie intake based on your goal:

• Lose weight: Eat 300-500 calories below your TDEE. This creates a calorie deficit that forces your body to burn stored fat for energy. A deficit of 500 calories per day typically results in about 1 pound of weight loss per week.
• Maintain weight: Eat at your TDEE. Your calorie intake matches your calorie burn, so your weight stays roughly the same.
• Gain muscle: Eat 300-500 calories above your TDEE. This calorie surplus provides the extra energy your body needs to build new muscle tissue, especially when combined with resistance training.

Macronutrients: Protein, Carbs, and Fat

While calories determine whether you lose, maintain, or gain weight, macronutrients determine the quality of your results. A common starting split is:

• Protein: 30% of total calories (supports muscle repair and growth)
• Carbohydrates: 40% of total calories (primary energy source)
• Fat: 30% of total calories (hormone production and nutrient absorption)

For our example TDEE of 2,633 calories with a weight-loss goal (eating 2,133 calories): Protein = 160g, Carbs = 213g, Fat = 71g. The Calnivo Calorie Calculator provides these macro targets automatically.

Important Considerations

BMR and TDEE are estimates, not exact measurements. Individual variation in metabolism, body composition, genetics, and hormonal factors means your actual calorie burn may differ from the calculated value. It is best to use TDEE as a starting point, track your results for 2-3 weeks, and adjust based on whether you are losing, maintaining, or gaining weight as expected.

Also, drastically reducing calories below your BMR is not recommended without medical supervision. Very low calorie diets can lead to muscle loss, nutrient deficiencies, metabolic adaptation, and other health problems. A moderate deficit of 300-500 calories is generally safe and sustainable for most adults.

Using the Calorie Calculator

Calnivo's free Calorie Calculator uses the Mifflin-St Jeor equation and provides your BMR, TDEE, goal-specific calorie targets, and macro breakdown — all in one place. Enter your age, gender, height, weight, activity level, and goal to get started.

Important Disclaimer

Calorie and macro calculations are estimates for general educational purposes. This article is not medical or nutritional advice. Individual needs vary based on health conditions, medications, and activity levels. Consult a healthcare provider or registered dietitian before making significant changes to your diet, especially if you have any medical conditions.