Calorie Calculator

📖 What are Calories?

A calorie (kcal) is a unit of energy. In nutrition, it measures the energy food provides and the energy your body uses. Managing calorie intake relative to calorie expenditure is the foundation of weight management.

🔬 BMR — Basal Metabolic Rate

Your BMR is the number of calories your body needs to sustain basic life functions (breathing, circulation, cell production) at rest. It accounts for roughly 60–75% of total daily energy expenditure for most people.

• Mifflin-St Jeor — the most widely validated formula for the general population.
• Revised Harris-Benedict — a classic formula, slightly less accurate than Mifflin for most people.
• Katch-McArdle — accounts for lean body mass; best if you know your body fat percentage.

⚡ TDEE — Total Daily Energy Expenditure

Your TDEE (maintenance calories) is your BMR multiplied by an activity factor. Eat below TDEE to lose weight; eat above to gain.

⚖️ Calorie Goals

• A 500 kcal/day deficit typically produces ~0.5 kg (1 lb) of weight loss per week.
• A 500 kcal/day surplus typically produces ~0.5 kg of weight gain per week.
• Do not go below 1200 kcal/day (women) or 1500 kcal/day (men) without medical supervision.

⚠️ Limitations

• All formulas are statistical estimates — individual metabolism varies significantly.
• Calorie needs change with age, muscle mass, hormones, and health conditions.
• Tracking both calories consumed and expended improves accuracy.