Calorie Calculator

TDEE (Total Daily Energy Expenditure) is the total calories you burn daily including: BMR (basal metabolic rate - calories for basic body functions), physical activity, and food digestion. Our calculator uses the Mifflin-St Jeor equation to compute BMR: Men = (10 × weight kg) + (6.25 × height cm) - (5 × age) + 5; Women = same formula - 161 instead of + 5. Then multiply BMR by activity factor (1.2 sedentary to 1.9 very active) = TDEE. Example: 30-year-old woman, 65kg, 165cm, moderate activity: BMR ≈ 1,380; TDEE ≈ 2,139 calories/day.

BMR (Basal Metabolic Rate) is calories your body burns at complete rest maintaining vital functions: breathing, circulation, cell production, and temperature regulation. BMR accounts for 60-75% of total daily calories burned. It's crucial for weight management because: (1) It sets your minimum calorie needs - eating below BMR long-term is unhealthy and slows metabolism; (2) Understanding BMR helps calculate safe calorie deficits; (3) BMR decreases with age and weight loss, requiring calorie adjustment. Our calculator provides accurate BMR using proven scientific formulas.

Safe calorie deficits for weight loss: 500 calories/day = 1 pound/week loss; 750 calories/day = 1.5 pounds/week; 1,000 calories/day = 2 pounds/week (maximum safe rate). Never eat below your BMR or below 1,200 calories (women) / 1,500 calories (men) without medical supervision. Extreme deficits cause: muscle loss, metabolism slowdown, nutrient deficiencies, hormonal disruption. For sustainable weight loss: combine moderate calorie deficit (500-750 cal) with strength training to preserve muscle and boost metabolism. Our calculator shows safe calorie targets for various goals.

TDEE calculators using Mifflin-St Jeor equation are accurate within ±10% for most people - a good starting point. However, individual variations exist due to: genetics, muscle mass (muscle burns more calories), hormone levels (thyroid, cortisol), medications, and previous dieting history. Use calculated TDEE as baseline, then track weight for 2-3 weeks. If not losing/gaining as expected: adjust calories by 200-300 and reassess. Metabolic adaptation means TDEE decreases during weight loss, requiring periodic recalculation.

Activity level dramatically impacts TDEE. For same person (BMR = 1,500): Sedentary (1.2×) = 1,800 calories/day; Light activity (1.375×) = 2,063 calories; Moderate (1.55×) = 2,325 calories; High activity (1.725×) = 2,588 calories; Very high (1.9×) = 2,850 calories. That's a 1,050 calorie difference between sedentary and very active! Activity levels: Sedentary = desk job, no exercise; Light = light exercise 1-3 days/week; Moderate = moderate exercise 3-5 days; High = intense exercise 6-7 days; Very high = athlete-level training twice daily. Be honest with activity level for accurate results.