Mifflin-St Jeor formula with activity level
BMR (Basal Metabolic Rate) is the energy your body needs at rest — for heartbeat, breathing, cell maintenance. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor and equals your total daily calorie burn. To maintain weight, eat your TDEE.
BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + s, where s = +5 for men and −161 for women. Published in 1990, this formula is considered more accurate than the older Harris-Benedict equation and is preferred by nutritionists today.
1 kg of body fat equals about 7,700 kcal. A moderate 500 kcal/day deficit yields roughly 0.5 kg/week of weight loss. Deficits above 750-1000 kcal/day are not recommended — risk of muscle loss, hormonal issues and yo-yo dieting. For muscle gain, a surplus of 250-500 kcal/day is plenty.