BMR Calculator: Calculate Your Basal Metabolic Rate
BMR is the resting part of your calorie burn. It is useful, but it is not the number most people should eat from. Daily calorie targets usually come from TDEE, which adds activity to BMR.
What BMR tells you
BMR estimates how many calories your body burns at rest. It includes basic functions such as breathing, circulation, and maintaining body temperature.
TDEETools estimates BMR with Mifflin-St Jeor when body fat is not supplied. If body fat percentage is supplied, the calculator can use lean body mass to estimate resting needs.
Why BMR is lower than your daily calorie target
You do not spend the whole day at rest. Walking, work, training, digestion, and ordinary movement all add to the total. That is why the calculator turns BMR into TDEE with an activity multiplier.
If your BMR is 1,600 and your TDEE is 2,200, the 2,200 number is the maintenance estimate. Eating 1,600 would be a deficit for many people, not maintenance.
When body fat percentage helps
A credible body-fat estimate can help when body composition is far from average. More lean mass usually means a higher resting energy need.
Do not force a body-fat number if it is only a guess. A poor body-fat estimate can make the calculator less useful than leaving the field blank.
How to use BMR after calculating
Use BMR to understand the base of the estimate. Use TDEE to set calorie targets. Then use weekly weight trends to refine the number.
That distinction prevents a common mistake: treating resting calories as daily maintenance calories.
Sources and method notes
TDEETools articles explain calculator outputs in plain English. They are educational and are not medical advice.