TDEE is the total number of calories your body needs to maintain your current weight based on your activity level.

Formula:

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TDEE=BMR×Activity Level

Activity Level Multipliers:

Sedentary (little or no exercise): 1.2
Lightly active (light exercise/sports 1–3 days/week): 1.375
Moderately active (moderate exercise/sports 3–5 days/week): 1.55
Very active (hard exercise/sports 6–7 days a week): 1.725
Extra active (very hard exercise/physical job): 1.9