BMR is the energy consumed at complete rest, just for vital functions. TDEE adds all the day’s activity to BMR — walking, work, workouts — and represents how many calories you burn in a typical day.
The difference in caloric needs between a sedentary lifestyle and a very active one can exceed 600–800 kcal per day. If you increase your physical activity, you can maintain the same weight while eating significantly more.
The Mifflin-St Jeor formula provides a solid estimate, but does not take into account exact body composition or individual variations in metabolism. It is a good starting point, not a laboratory measurement.
This calculator is for informational purposes and does not constitute medical advice. Consult a doctor or nutritionist before making major changes to your diet — see the medical disclaimer.