Calculating Calorie Needs: BMR, TDEE & Macros

What Are Calorie Needs?

Your calorie needs are the amount of energy your body requires daily to maintain all functions – from breathing and heartbeat to training and everyday movement. They consist of two components: the Basal Metabolic Rate (BMR) and the Total Daily Energy Expenditure (TDEE).

Basal Metabolic Rate (BMR) – The Mifflin-St Jeor Formula

The basal metabolic rate is the energy your body needs at complete rest to maintain vital functions. The Mifflin-St Jeor formula (1990) is considered one of the most accurate estimation methods:

• Men: BMR = 10 × Weight (kg) + 6.25 × Height (cm) − 5 × Age + 5
• Women: BMR = 10 × Weight (kg) + 6.25 × Height (cm) − 5 × Age − 161

Example: A 30-year-old man, 80 kg, 180 cm: BMR = 10 × 80 + 6.25 × 180 − 5 × 30 + 5 = 800 + 1125 − 150 + 5 = 1780 kcal

Total Daily Energy Expenditure (TDEE) – The Activity Factor

TDEE takes your activity level into account. It shows how many calories you actually burn per day:

Example (continued): 1780 kcal × 1.55 (active) = 2759 kcal total expenditure

Goal Adjustment

TDEE is adjusted according to your goal:

• Lose weight: −500 kcal from TDEE → approx. 0.5 kg fat loss per week. A moderate deficit prevents muscle loss and is sustainable long-term.
• Maintain weight: Keep TDEE as is. Ideal for body recomposition (building muscle while losing fat).
• Gain weight: +400 kcal above TDEE → controlled gain. A moderate surplus minimises unwanted fat gain.

Important: A deficit of more than 500 kcal increases the risk of muscle loss and nutrient deficiency. Patience pays off.

Macronutrient Distribution

The recommended distribution is based on current nutritional guidelines for physically active individuals:

• Protein: ~30% of calories (1.6–2.0 g/kg body weight) – essential for muscle maintenance and growth
• Fat: ~25% of calories – important for hormones, vitamin absorption and cell health
• Carbohydrates: ~45% of calories – primary energy source for training and the brain

Example at 2200 kcal (losing weight):

Learn more about your individual protein needs in the article How Much Protein You Really Need.

Conclusion

Knowing your calorie needs is the first step towards targeted nutrition. The Mifflin-St Jeor formula provides a solid foundation – together with the appropriate activity factor and goal adjustment, you have a clear framework for your nutrition planning.

Calculate your individual needs directly with the Calorie Calculator. For the basics of a balanced diet, also check out our article Nutrition for Athletes.

Sources:

• Mifflin MD et al. (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition.
• Frankenfield D et al. (2005). Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults. Journal of the American Dietetic Association.
• Jäger R et al. (2017). International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition.