What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is what you burn in a coma—just keeping organs alive. TDEE (Total Daily Energy Expenditure) is BMR + the calories you burn walking, working, and exercising. TDEE is the number you need to eat to maintain weight.

Which BMR formula is best?

The Mifflin-St Jeor equation is currently considered the most accurate for the general population and is what the American Dietetic Association takes as the standard. The Harris-Benedict equation is older and tends to overestimate calories slightly.

Does muscle increase BMR?

Yes! Muscle tissue requires more energy to maintain than fat tissue. A more muscular person will have a higher BMR than a person of the same weight with higher body fat, meaning they burn more calories even while watching TV.

BMR Calculator | Calculate Basal Metabolic Rate | Finmato

The "Coma Calories" Caluclation

Most people obsess over how many calories they burn on the treadmill. But the truth is, the vast majority of your daily energy expenditure comes from simply being alive. Your heart beating, your brain thinking, your liver filtering—all of this requires energy. This baseline is your Basal Metabolic Rate (BMR).

Our BMR Calculator uses the gold-standard Mifflin-St Jeor equation to estimate this number. Once you know your baseline, you can build a diet plan that actually works, rather than just guessing.

From BMR to TDEE

Your BMR is the starting line. To get the full picture, we apply multipliers based on your lifestyle to find your Total Daily Energy Expenditure (TDEE).

BMR (The Floor)

This is the absolute minimum calories you need. Never eat below your BMR for extended periods, or your metabolism may slow down to "survival mode."

TDEE (The Ceiling)

This is your "maintenance" number. If you eat this amount, your weight stays the same. To lose weight, you eat slightly below this number (but above BMR).

Understanding Activity Levels

Be honest here! Overestimating your activity is the #1 reason diets fail.

Sedentary (BMR x 1.2): Desk job, little to no exercise. (Most people fall here).
Lightly Active (BMR x 1.375): Light exercise/sports 1-3 days/week.
Moderately Active (BMR x 1.55): Moderate exercise/sports 3-5 days/week.
Very Active (BMR x 1.725): Hard exercise/sports 6-7 days a week.

Safe Cutting

Bodybuilders use BMR to calculate the maximum calorie deficit they can sustain without losing muscle mass during a cut.

Reverse Dieting

If you have been starving yourself and not losing weight, you might need to slowly increase calories back to your true TDEE to "reboot" your metabolism.

Bulking Up

To gain muscle, you must be in a surplus. Knowing your TDEE allows you to eat just enough to grow muscle without gaining excessive fat (Total + 300-500 cal).

Frequently Asked Questions

Why does BMR go down as I lose weight?

Smaller bodies require less energy to maintain. This is why weight loss often stalls (plateaus); as you get lighter, your calorie needs drop, and you must adjust your diet further.

Does age lower BMR?

Generally, yes. Metabolism tends to slow by about 2-3% per decade after age 20, largely due to muscle loss. Staying active and lifting weights can counteract this.

Is the Katch-McArdle formula better?

The Katch-McArdle formula requires you to know your body fat percentage. If you have that data (from our Body Fat Calculator), it is more accurate than Mifflin-St Jeor because it accounts for lean muscle mass.

Medical Disclaimer

This tool provides an estimation for general informational purposes. Hormonal conditions (hypothyroidism) and medications can significantly alter true BMR.

Data Privacy

We do not store your physical data. This tool runs entirely in your browser.

BMR Calculator