How TDEE is Calculated
TDEE is the product of two values: your Basal Metabolic Rate (BMR) and your Activity Multiplier.
Your BMR is the number of calories your body needs to perform basic life-sustaining functions — breathing, circulation, cell production — while at complete rest. It is typically 60–70% of your total daily energy expenditure.
The Mifflin-St Jeor Equation
The most widely recommended formula for estimating BMR is the Mifflin-St Jeor equation, which the American Dietetic Association endorses as the most accurate for the general population:
For males:
BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
For females:
BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Activity Multipliers
Once you have your BMR, multiply it by an activity factor based on your daily movement level:
| Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Desk job, little exercise |
| Light | 1.375 | Exercise 1–3 days/week |
| Moderate | 1.55 | Exercise 3–5 days/week |
| Active | 1.725 | Hard exercise 6–7 days/week |
| Very Active | 1.9 | Athlete or physical job |
Why TDEE Matters
Knowing your TDEE is the foundation of any nutrition plan. Whether your goal is weight loss, muscle gain, or maintenance, everything starts with understanding how many calories you burn.
- Weight Loss: Eat below your TDEE. A deficit of 500 kcal/day results in approximately 0.5 kg (1 lb) of fat loss per week.
- Weight Gain: Eat above your TDEE. A surplus of 500 kcal/day supports approximately 0.5 kg of weight gain per week.
- Maintenance: Eat at your TDEE to maintain your current weight.
TDEE vs BMR
BMR is the calories your body burns at complete rest. TDEE includes BMR plus all the calories burned through daily activities and exercise. Think of BMR as your "engine idle" and TDEE as your "total fuel consumption." Learn more in our BMR vs TDEE comparison.
Factors That Affect TDEE
Several factors influence your TDEE beyond just BMR and activity level:
- Age: Metabolism slows approximately 1–2% per decade after age 20.
- Body Composition: Muscle tissue burns more calories at rest than fat tissue.
- Genetics: Some people naturally have faster or slower metabolisms.
- Hormones: Thyroid hormones, cortisol, and insulin sensitivity all play roles.
- Thermic Effect of Food (TEF): Your body burns calories digesting food — roughly 10% of total intake.
How to Use Your TDEE
The most practical approach: track your intake and weight for 2–3 weeks while eating consistently. If your weight stays stable, you're eating at your TDEE. If you gain or lose, adjust by 100–200 calories and reassess.
Ready to find your number? Use our free TDEE calculator to get instant, personalized results.