What Is TDEE (Total Daily Energy Expenditure)?
Your TDEE is the total number of calories your body burns in a 24-hour period, including sleeping, working, exercising, and digesting food (British Nutrition Foundation; NHS Calorie Counting Guidance).
The TDEE Formula Components
Most standard clinical calculators estimate your resting needs first using the Mifflin–St Jeor equation (Mifflin et al., 1990), which predicts resting energy expenditure from weight, height, age, and sex:
TDEE = BMR × Activity Multiplier
- BMR (Basal Metabolic Rate): Calories burned at complete rest (PMC predictive REE equation study).
- Sedentary (Little/no exercise): BMR × 1.2
- Lightly Active (1-3 days/wk): BMR × 1.375
- Moderate Exercise (3-5 days/wk): BMR × 1.55
- Heavy Exercise (6-7 days/wk): BMR × 1.725
Calorie Goals Breakdown
According to the British Dietetic Association (BDA), a safe and realistic target for adult fat loss is approximately 0.5 to 1 kg (1 to 2 lbs) per week:
- Maintenance: Eat 100% of TDEE (NHS reference daily intake: ~2,000 kcal for women, ~2,500 kcal for men).
- Fat Loss (Deficit): Subtract 500–600 kcal/day from maintenance for sustainable weekly weight loss (Hall & Chow, 2013).
- Muscle Gain (Surplus): Add 250–500 kcal/day to support muscle tissue synthesis.