How many calories should I eat per day to maintain my weight?
Daily calorie needs vary widely: sedentary women typically need 1,600–2,000 kcal; sedentary men need 2,000–2,600 kcal. Active individuals need 2,200–3,000+ kcal. This calculator uses the Mifflin-St Jeor equation multiplied by an activity factor to give your TDEE — eat at this level to maintain your current weight.
How many calories do I need to lose 1 kg per week?
1 kg of body fat contains approximately 7,700 kcal. To lose 1 kg/week, you need a daily deficit of 7,700 ÷ 7 = 1,100 kcal — which is aggressive and unsustainable for most people. A more realistic target is 0.5 kg/week (500 kcal deficit/day). This preserves muscle mass, maintains energy levels, and is far more achievable long-term.
What activity multiplier should I choose?
Sedentary (×1.2): desk job, no exercise. Lightly active (×1.375): light exercise 1–3 days/week. Moderately active (×1.55): moderate exercise 3–5 days/week. Very active (×1.725): hard exercise 6–7 days/week. Extra active (×1.9): very hard daily exercise or physical job + training. Most people overestimate their activity level — when in doubt, choose one level lower.
Do calorie needs change with age?
Yes — calorie needs typically decrease with age due to reduced muscle mass, lower hormone levels, and decreased activity. Between ages 20 and 70, BMR can drop by 15–20%. A 50-year-old man may need 200–300 fewer calories per day than a 25-year-old of the same weight. Maintaining muscle through resistance training partially counteracts this decline.
Are all calories equal — does food quality matter?
For weight management, total calories matter most (calories in vs calories out). However, food quality significantly affects hunger, energy levels, nutrient intake, and health outcomes. 500 kcal of chicken and vegetables is far more filling and nutritious than 500 kcal of biscuits, even though the calorie count is identical. For sustainable results, combine calorie awareness with whole-food nutrition.