TDEE is a personalized measurement that includes all the calories you burn from daily activities, like breathing, digestion, brain functions, and physical activity.

Total Daily Energy Expenditure is calculated by checking BMR (Basal Metabolic Rate) or how much we are burning during resting and adding some more depending on how often we exercise.

So, the formula to calculate TDEE is;

TDEE = BMR + Few Additional Calories as per activity

To measure your TDEE accurately, 

• Use the estimated TDEE value and consume this number of calories every day.
• Monitor weight changes.
• Find calorie value where weight doesn't change and that is your TDEE.

If you want to check a BMR and TDEE Calculator, you can click here. This will give you an estimate of how much is your BMR and TDEE which you can use to check using the above method.

Or you can directly also use these values because these are approximately accurate only and you will only find a few calories here and there.