What is TDEE?
Total daily energy expenditure: basal metabolic rate multiplied by an activity factor.
Activity factors run from about 1.2 for sedentary to 1.9 for very active. Because BMR itself carries roughly ±10% individual error, TDEE inherits it, which is why it belongs on a page as a range rather than a target.
Not to be confused with BMR
BMR is what the body uses at complete rest. TDEE adds everything else you do, and the gap between them is usually 20–90% of BMR.