TDEE — Total Daily Energy Expenditure — is the total number of calories your body burns in a day. It's the single most important number in any diet or body composition plan: eat below it to lose weight, above it to gain, and at it to maintain.
What Makes Up Your TDEE?
- BMR (60–75%): The calories your body burns to stay alive — breathing, circulation, cell repair. Even completely at rest, you'd burn your BMR.
- TEF (~10%): The energy cost of digesting food. Protein has the highest TEF (20–30%), then carbs (5–10%), then fat (0–3%).
- Exercise (variable): Calories burned during intentional workouts — the component most people overestimate.
- NEAT (15–30%): Non-Exercise Activity Thermogenesis — walking, fidgeting, standing, typing. Often varies by 500+ calories per day between individuals and is massively underestimated.
How to Calculate TDEE
Start with the Mifflin-St Jeor equation for BMR:
BMR (men) = 10W + 6.25H − 5A + 5BMR (women) = 10W + 6.25H − 5A − 161(W = kg · H = cm · A = age)
Then multiply by your activity factor:
Activity LevelDescriptionMultiplier
SedentaryDesk job, little movement× 1.2
Lightly active1–3 days/week exercise× 1.375
Moderately active3–5 days/week× 1.55
Very active6–7 days/week hard training× 1.725
Extra activePhysical job + daily training× 1.9
Using TDEE for Fat Loss
A 500 cal/day deficit creates roughly 0.5 kg weekly fat loss. Guidelines:
- Mild deficit (10–15%): Best for muscle retention. Sustainable long-term.
- Moderate (20–25%): Faster results. Requires higher protein to preserve muscle.
- Aggressive (>25%): Not recommended — increases muscle loss, metabolic adaptation, and nutrient deficiencies.
Why TDEE Changes Over Time
As you lose weight, your TDEE drops — a smaller body needs less energy. Recalculate every 4–6 weeks. NEAT also decreases during calorie restriction (you unconsciously move less), which can reduce effective TDEE by an additional 10–15% beyond what body weight alone predicts.