Total daily energy expenditure, TDEE, is the number of calories you burn in a day, and it is the anchor for every calorie goal. It is your basal rate, the energy your body uses at rest, multiplied by how active you are. Get TDEE right and a target for losing, holding or gaining weight is simple arithmetic; get it wrong and no diet adds up.
TDEE versus BMR
BMR, the basal metabolic rate, is what you burn at complete rest; TDEE is BMR scaled up by activity, so TDEE vs BMR is really rest versus a whole day. BMR is estimated from your weight, height, age and sex by well-established equations, and an activity multiplier turns it into TDEE, which is the number a calorie target is built on.
How the estimate is built
The common approach estimates BMR with an equation such as Mifflin-St Jeor, then multiplies by an activity factor from sedentary to very active. What is my TDEE is therefore an estimate with a margin, because activity is hard to self-report; the honest use is to take the number as a starting point and adjust it against how your weight actually moves over a few weeks.
Turning TDEE into a goal
Once you have TDEE, a target follows directly: eat around it to hold weight, below it to lose, above it to gain. The size of the gap sets the pace. Because the estimate has a margin, the real calibration is watching the scale trend, not trusting the calculated number to the calorie, which is where the free calorie tools on this site take over.
Questions people ask about total daily energy expenditure
What is TDEE?
Total daily energy expenditure is the calories you burn in a day: your basal metabolic rate multiplied by an activity factor, and the anchor every calorie goal is built on.
What is the difference between TDEE and BMR?
BMR is what you burn at complete rest; TDEE is BMR scaled up by how active you are, so TDEE is always higher and is the number a daily calorie target uses.
What is my TDEE, exactly?
It is an estimate with a margin, because activity is hard to self-report; take the calculated figure as a starting point and adjust it against how your weight actually moves.