How TDEE Is Calculated
First, BMR is calculated using Mifflin-St Jeor: Men = 10*weight + 6.25*height - 5*age - 5. Women = 10*weight + 6.25*height - 5*age - 161. Then multiply by activity factor.
Activity Multipliers
Sedentary (1.2), Light (1.375), Moderate (1.55), Active (1.725), Very Active (1.9). The result is your estimated daily calorie needs for weight maintenance.