BMR (basal metabolic rate) is the energy you burn doing nothing at all; TDEE (total daily energy expenditure) is BMR plus movement, exercise and digestion, so it is always higher. For a 35-year-old woman at 165 lb, BMR is 1,444 kcal and TDEE is 2,239. Plan your intake around TDEE, and treat BMR as a floor, not a target.
Key takeaways
- TDEE is BMR multiplied by an activity factor (1.2 to 1.9), so it is 20–90% higher than BMR.
- Base your calorie target on TDEE, then adjust: about 10–20% below it to lose fat, at it to maintain.
- Eating below your BMR is not a normal plan and should happen only under medical supervision.
- BMR and RMR are nearly the same number; RMR is measured under looser conditions and runs a few percent higher.
- TDEE and maintenance calories are the same thing for planning purposes.
Both numbers come from the same family of formulas, and mixing them up is the most common calorie-planning mistake. The short version: BMR is a piece of TDEE. You can calculate both at once with the TDEE calculator or the BMR calculator.
What is the difference between TDEE and BMR?
BMR is the energy your body needs to stay alive while completely at rest: powering organs, breathing, circulation and body temperature. TDEE is everything you burn in a day: BMR, plus non-exercise movement, workouts and digesting food (Westerterp, 2004; Levine, 2002). See what TDEE is for the full breakdown.
| Measure | BMR | RMR | TDEE (maintenance) |
|---|---|---|---|
| Meaning | Energy at complete rest | Energy at rest, easier conditions | Energy for the whole day |
| Includes movement? | No | No | Yes |
| Includes digestion? | No | No | Yes |
| Typical share of TDEE | About 60–70% | A few percent above BMR | 100% |
| Example woman (35, 165 lb, 5′5″) | 1,444 kcal | About 1,444 (same equation) | 2,239 kcal |
| Example man (30, 190 lb, 5′10″) | 1,828 kcal | About 1,828 (same equation) | 2,834 kcal |
| Use it for | Floor for safe intakes | Same as BMR | Setting your calorie target |
TDEE values assume moderate activity (BMR × 1.55). The example numbers use the Mifflin–St Jeor equation (Mifflin et al., 1990).
How do you convert BMR to TDEE?
Multiply BMR by an activity factor. For our example woman, whose BMR is 1,444 kcal:
| Activity level | Factor | TDEE |
|---|---|---|
| Sedentary | 1.2 | 1,733 kcal |
| Light | 1.375 | 1,986 kcal |
| Moderate | 1.55 | 2,239 kcal |
| Active | 1.725 | 2,491 kcal |
| Athlete | 1.9 | 2,744 kcal |
So her TDEE sits between 1,733 and 2,744 kcal depending on lifestyle, against a BMR that does not change. Most people overestimate their activity, so when unsure pick the lower factor and adjust from your results.
Should I eat my BMR or my TDEE?
Eat around your TDEE, or a modest percentage below it. Your BMR is the cost of staying alive at rest, not a meal plan.
- To maintain weight: eat at TDEE (2,239 kcal for our example woman).
- To lose fat: eat 10–20% below TDEE, which is 1,791–2,015 kcal for her. That is 347–571 kcal above her BMR.
- To gain muscle: eat 5–10% above TDEE.
The common advice to “eat your BMR to lose weight” mixes up the two. Eating your BMR is a deficit of about 35% of TDEE for her, which is aggressive. At that level it gets hard to hit protein targets, and the extra loss is more likely to include muscle.
What does eating below BMR actually do?
Your body does not “shut down” in a single day of low intake, and the claim that it enters “starvation mode” immediately is overstated. But a long, steep deficit has real costs: it becomes difficult to get enough protein and micronutrients, training suffers, and adaptation can lower expenditure somewhat beyond what lost weight alone explains (Rosenbaum & Leibel, 2010). A moderate deficit gets you the same fat loss in a safer, more sustainable way. See the calorie deficit guide.
How is BMR different from RMR?
BMR is measured after sleep, fasted, still and awake. RMR is measured with fewer restrictions, so it reads a few percent higher. In practice the equations blur the two. Mifflin–St Jeor was built on resting measurements, and systematic reviews of predictive equations treat resting energy as one target (Frankenfield et al., 2005). For daily planning the gap is smaller than the error in your activity factor. Use the RMR calculator for a resting estimate.
How is TDEE different from maintenance calories?
They are the same quantity from two angles. TDEE is the energy you burn. Maintenance calories are the food intake that keeps weight stable, which equals it. Since TDEE is estimated, treat the figure as a starting point: eat it for 2–4 weeks and see whether your weight trend is flat. If not, adjust, or learn your real number with adaptive TDEE.
Frequently asked questions
Should I eat my BMR or my TDEE?
Eat around your TDEE to maintain weight, or 10–20% below it to lose fat. Your BMR is the energy your body needs at rest, so it works as a floor rather than a goal. A fat-loss target for most people stays well above BMR. Use the calorie deficit calculator to check.
What happens if I eat below my BMR?
Occasionally eating below BMR is not dangerous in itself, but doing it for weeks makes it hard to meet protein and micronutrient needs and increases the risk of muscle loss, fatigue and rebound eating. Avoid it unless a doctor or registered dietitian supervises.
Is it OK to eat below BMR to lose weight faster?
Usually unnecessary. A moderate deficit of 15–20% below TDEE leaves intake above BMR for most people, and bigger deficits mostly cost muscle and adherence. If your target falls under BMR, extend the timeline or add daily movement instead.
Is BMR the same as RMR?
Close. BMR is measured fasted, fully rested and awake in a thermoneutral room; resting metabolic rate (RMR) is measured under easier conditions and runs a few percent higher. Mifflin–St Jeor was derived from RMR data, and most calculators use the terms interchangeably. Try the RMR calculator.
Is TDEE the same as maintenance calories?
Yes. Maintenance calories are the intake at which your weight stays stable, which equals your total daily energy expenditure. The difference is only wording: TDEE is the energy you burn, maintenance is the matching intake.
Do I need to add exercise calories to my TDEE?
No, if you chose an activity factor that already reflects your training. The factor includes typical exercise, so adding workout calories on top double-counts them. Add exercise only if you used the sedentary factor and want to track workouts separately.
References
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition 51(2):241–247.
- Frankenfield D, Roth-Yousey L, Compher C (2005). Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association 105(5):775–789.
- Westerterp KR (2004). Diet induced thermogenesis. Nutrition & Metabolism 1:5.
- Levine JA (2002). Non-exercise activity thermogenesis (NEAT). Best Practice & Research Clinical Endocrinology & Metabolism 16(4):679–702.
- Rosenbaum M, Leibel RL (2010). Adaptive thermogenesis in humans. International Journal of Obesity 34(Suppl 1):S47–S55.