How Many Calories Do You Need Per Day?
Your daily calorie needs depend on several personal factors — age, sex, current weight, height and how physically active you are. This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate formula for estimating calorie needs by nutrition professionals and dietitians worldwide.
The result you get is your TDEE (Total Daily Energy Expenditure) — the total number of calories your body needs to maintain your current weight given your activity level.
How to Use the Results
- To lose weight: Eat approximately 500 calories below your TDEE. This creates a deficit that leads to roughly 0.5kg (1lb) of fat loss per week — a safe, sustainable rate.
- To maintain weight: Eat at your TDEE. Your weight will stay stable.
- To gain weight: Eat approximately 500 calories above your TDEE to gain roughly 0.5kg per week.
What is BMR?
BMR stands for Basal Metabolic Rate — the number of calories your body burns just to stay alive at complete rest (breathing, circulation, organ function). It represents your absolute minimum calorie needs. Most people should never eat below their BMR.
What is TDEE?
TDEE stands for Total Daily Energy Expenditure. It is your BMR multiplied by an activity factor that accounts for how much you move throughout the day. TDEE is your true maintenance calorie level — the number you use as your starting point for any diet goal.
Understanding Activity Levels
- Sedentary: Desk job, little walking, no planned exercise
- Lightly active: Light walking or exercise 1–3 days per week
- Moderately active: Exercise or sports 3–5 days per week
- Very active: Hard exercise or physical job 6–7 days per week
- Extra active: Very intense daily training or extremely physical work
Most people overestimate their activity level. When in doubt, choose one level lower than you think — it leads to more accurate results.
Frequently Asked Questions
How accurate is this calorie calculator? +
The calculator uses the Mifflin-St Jeor equation which is accurate to within 10% for most people. Individual variation exists due to genetics, muscle mass, hormones and health conditions. Use the result as a starting point and adjust based on real-world results over 2–3 weeks.
How many calories should I eat to lose weight fast? +
A deficit of 500 calories per day is the gold standard for safe weight loss — approximately 0.5kg (1lb) per week. Deficits larger than 1,000 calories per day are generally not recommended as they can cause muscle loss, nutrient deficiencies and metabolic slowdown.
Should I eat below my BMR? +
No. Eating below your BMR for extended periods can slow your metabolism, cause muscle loss and lead to nutritional deficiencies. Your BMR is the minimum your body needs just to function. Always aim to stay above it.
Why are my calorie needs different from my friend's? +
Calorie needs vary significantly between individuals because of differences in body size, muscle mass, age, sex and activity. A larger, more muscular, younger, more active person will always have higher calorie needs than a smaller, older, less active person.
What are macros and why do they matter? +
Macros (macronutrients) are protein, carbohydrates and fat — the three main sources of calories. Protein (4 cal/g) supports muscle. Carbs (4 cal/g) provide energy. Fat (9 cal/g) supports hormones and brain function. Balancing macros helps body composition, energy and health beyond just counting total calories.
