TDEE calculator and what the number means
Total daily energy expenditure is every calorie your body burns in a day: resting metabolism, digestion, movement and exercise. Estimate yours below, then learn how an Apple Watch measures it instead.
TDEE calculator
Mifflin-St Jeor equation. An estimate from population averages, not a measurement of you.
What TDEE is
TDEE is the sum of four things: your basal metabolic rate (the energy that keeps you alive at rest), the thermic effect of food (digestion, roughly 10% of intake), non-exercise activity like walking and fidgeting, and deliberate exercise. For most people resting metabolism is 60 to 70% of the total, which is why two people who train the same can have very different daily burns.
How the calculator works
It estimates BMR with the Mifflin-St Jeor equation, the formula with the best accuracy in validation studies for the general population, then multiplies by an activity factor.
BMR (women) = 10 x kg + 6.25 x cm - 5 x age - 161
TDEE = BMR x activity factor (1.2 to 1.9)
| Activity | Factor | Who this fits |
|---|---|---|
| Sedentary | 1.2 | Desk job, under 5,000 steps, no training |
| Light | 1.375 | Exercise 1 to 3 days a week |
| Moderate | 1.55 | Exercise 3 to 5 days a week |
| Active | 1.725 | Hard training 6 to 7 days a week |
| Very active | 1.9 | Physical job plus daily training |
Why the estimate is often wrong for you
The activity factor is a guess, and most people pick one level too high. A 1.55 versus 1.375 choice moves the result by about 300 kcal a day, which is the entire margin of a typical fat-loss deficit. The equation also knows nothing about your muscle mass, your sleep, or whether you walked 4,000 or 14,000 steps today.
Measuring TDEE with an Apple Watch
An Apple Watch records two numbers in Apple Health all day: resting energy, its model of your BMR spread across the day, and active energy, calories above resting from heart rate and motion. Add them and you have a measured total daily energy expenditure for that specific day, not a population average. The Move ring only shows the active half, which is why it reads so much lower than any TDEE calculator.
Total Calories does that addition for you and keeps the daily history, so a 7-day or 30-day average becomes your working TDEE. That rolling average is more useful than any formula: it already includes your real steps, workouts and lazy Sundays.
Using the number
- To maintain weight, eat roughly at your average total burn.
- For fat loss, a deficit of 300 to 500 kcal a day below your measured average is the usual starting point. Bigger is not better for long.
- Recheck every few weeks. Your burn drops as you lose weight and climbs as you move more.
Informational only, not medical advice. Talk to a clinician before changing your diet if you have a medical condition.
Common questions
Is TDEE the same as calories burned?
Yes. TDEE is the total calories burned in a day, including resting metabolism, digestion and all movement. Fitness trackers usually show only the active portion, so their number is lower than your TDEE.
How accurate is a TDEE calculator?
Formula estimates are typically within about 10% for an average adult, but the activity multiplier is a guess and can add several hundred calories of error. A measured 7 to 30 day average from an Apple Watch reflects your own days instead.
What is a normal TDEE?
Most adults fall between 1,600 and 3,000 kcal a day. Larger, younger, more muscular and more active people sit at the top of that range.