TDEE — Total Daily Energy Expenditure — is the total number of calories your body burns in a 24-hour period. It accounts for everything: breathing, digestion, walking, exercise, even thinking. It is the single most useful number for anyone trying to manage their weight.
TDEE vs BMR — What's the Difference?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — lying still, doing nothing. It keeps your heart beating, lungs breathing, and organs functioning.
TDEE is BMR multiplied by your activity level. Because we all move throughout the day, TDEE is always higher than BMR. For most people, TDEE is 20–90% higher than their BMR depending on how active they are.
How TDEE is Calculated
The most accurate approach uses the Mifflin-St Jeor equation — validated in clinical research as the most reliable formula for most adults:
Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
TDEE = BMR × Activity Multiplier
Activity Multipliers
| Activity Level | Description | Multiplier |
|---|---|---|
| Sedentary | Desk job, little or no exercise | × 1.2 |
| Lightly active | Light exercise 1–3 days/week | × 1.375 |
| Moderately active | Moderate exercise 3–5 days/week | × 1.55 |
| Very active | Hard exercise 6–7 days/week | × 1.725 |
| Extra active | Twice daily training or physical job | × 1.9 |
Using TDEE for Weight Management
Once you know your TDEE, the arithmetic of weight management becomes simple:
- To lose weight: Eat 300–500 calories below your TDEE. A 500 calorie daily deficit = approximately 0.5kg (1lb) loss per week.
- To maintain weight: Eat at your TDEE.
- To gain weight: Eat 250–500 calories above your TDEE. This creates a surplus that supports muscle gain when combined with strength training.
How Accurate is TDEE?
The Mifflin-St Jeor equation is accurate to within 10% for most adults. The biggest source of error is the activity multiplier — most people overestimate how active they are. If you're not losing weight despite eating at a supposed deficit, try using the "lightly active" multiplier instead of "moderately active" and reassess after two weeks.
TDEE also changes over time. As you lose weight, your TDEE decreases. Recalculate every 4–6 weeks to keep your targets accurate.
Why TDEE Beats Calorie Counting Apps
Most calorie-counting apps use a fixed recommendation (1,200 for women, 1,500 for men) that ignores your individual size and activity. These generic targets can leave larger individuals under-fuelled and smaller individuals eating too much. TDEE gives you a personalised starting point based on your actual physiology.