BMR vs TDEE: What's the Difference?
If you have started tracking calories, you have probably seen two acronyms: BMR and TDEE. They are related but measure different things, and mixing them up can wreck a diet plan.
What is BMR?
BMR (basal metabolic rate) is the energy your body burns at complete rest just to stay alive - breathing, circulating blood, regulating temperature, and repairing cells. It typically accounts for 60-70% of the calories you burn each day.
Estimate yours with the BMR Calculator, which uses the Mifflin-St Jeor and Harris-Benedict formulas.
What is TDEE?
TDEE (total daily energy expenditure) is everything you burn in a day: your BMR plus movement, exercise, and the energy used to digest food. It is the number that actually determines whether you gain, lose, or maintain weight.
TDEE is calculated as BMR multiplied by an activity factor:
- Sedentary (little exercise): BMR x 1.2
- Lightly active (1-3 days/week): BMR x 1.375
- Moderately active (3-5 days): BMR x 1.55
- Very active (6-7 days): BMR x 1.725
- Athlete (twice daily training): BMR x 1.9
Why the difference matters
You should base your calorie target on TDEE, not BMR. Eating only your BMR while active creates a very large deficit that is hard to sustain and can cost you muscle. Conversely, treating your BMR as your "maintenance" can make you under-eat without realizing it.
How to use them together
- Calculate BMR first as your baseline.
- Apply an activity multiplier to get TDEE (maintenance).
- To lose fat, eat 300-500 kcal below TDEE.
- To gain muscle, eat 200-350 kcal above TDEE.
The TDEE Calculator does both steps and gives you maintenance, loss, and gain targets at once.