About this calculator
Total Daily Energy Expenditure (TDEE) is the total calories you burn in a day — basal metabolic rate (BMR, your at-rest calorie burn) multiplied by an activity factor. Knowing your TDEE is the starting point for any dietary plan: eat at TDEE to maintain, below to lose, above to gain.
The Mifflin-St Jeor formula
Most accurate BMR formula for the general population:
- Men: BMR = 10 × kg + 6.25 × cm − 5 × age + 5
- Women: BMR = 10 × kg + 6.25 × cm − 5 × age − 161
TDEE = BMR × activity multiplier (1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 active, 1.9 very active). Most office workers fall into "light" or "moderate" — almost no one is "sedentary" if they walk at all during the day.
Activity level — most people overestimate
- Sedentary — desk job + no intentional exercise. Truly. If you walk to lunch, you’re probably "light."
- Light — light exercise 1–3 days/week, or a non-desk job.
- Moderate — moderate exercise 3–5 days/week.
- Active — hard exercise 6–7 days/week, or physical labor + training.
- Very active — daily intense training + physical job. Athletes only.
Why TDEE estimates are ±10–15%
BMR varies between individuals at the same height/weight/age due to muscle mass differences, thyroid function, NEAT (non-exercise activity thermogenesis — fidgeting, posture), and metabolic adaptation history. The only accurate TDEE measurement is empirical: track calorie intake at known body weight for 2–3 weeks. If weight is stable, that intake = your TDEE.
TDEE during dieting
Sustained caloric deficits cause metabolic adaptation — TDEE drops as the body becomes more efficient. A 10–20% TDEE reduction is typical after 12 weeks of dieting. This is why weight loss stalls; the same intake that was a 500-cal deficit becomes a 200-cal deficit. Diet breaks (eating at maintenance for 1–2 weeks) help reset metabolism.