What is BMR?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — without movement, digestion or external activity. It is the energy that goes to keeping the heart, lungs, brain and organs running.
BMR is calculated with formulas like Mifflin-St Jeor or Harris-Benedict, based on gender, age, weight and height. It is the starting point for all calorie calculations — but it is not the number you should eat at.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is the calories you actually burn during a day — including all movement and activity. TDEE is calculated as:
PAL (Physical Activity Level) ranges from 1.3 for sedentary to 2.1 or more for very active. TDEE includes planned exercise (EAT), spontaneous movement (NEAT) and the energy cost of digestion (TEF).
Comparison: BMR vs TDEE
| Property | BMR | TDEE |
|---|---|---|
| What is measured? | Resting burn rate | Total daily burn |
| Includes activity? | No | Yes |
| Includes exercise? | No | Yes |
| Includes digestion? | No | Yes (TEF) |
| Used for? | Calculation base | Calorie goals and planning |
| Typical level (70 kg, active) | ~1,600 kcal | ~2,500 kcal |
Why you should always use TDEE
Planning calories based on BMR creates an uncontrolled deficit. Example: a person with BMR 1,700 kcal and TDEE 2,400 kcal who eats 1,700 kcal thinks they are at maintenance — but are actually in a 700 kcal deficit.
This leads to rapid weight loss initially, but with significant muscle mass loss and metabolic adaptation. The body lowers BMR to save energy, making it harder to sustain weight loss.
Right approach: calculate your TDEE and create a controlled deficit of — sufficient for sustainable weight loss without sacrificing muscle mass.