Plain-language meaning
BMR estimates how much energy the body uses for basic functions at rest. Calorie calculators often multiply BMR by an activity factor to estimate total daily energy expenditure.
How it affects calculator results
BMR is the base number before activity is added. If the BMR estimate is off, the TDEE and calorie target built from it will also be off.
What to check
- Check which BMR equation is being used, such as Mifflin-St Jeor or Harris-Benedict.
- Use consistent height and weight units.
- Do not treat BMR as a measured metabolic test unless it came from a clinical measurement.
Limitations
BMR equations are population estimates and may not reflect individual health, body composition, medication, pregnancy, breastfeeding or training status.
FAQ
Is BMR the same as maintenance calories?
No. Maintenance calories usually mean TDEE, which adds activity to BMR.
Can BMR be measured directly?
Resting energy expenditure can be measured with clinical equipment, but online calculators estimate it from equations.