metabolism
Basal Metabolic Rate (BMR)
The minimum number of calories your body needs per day at complete rest, with no digestion or activity, to maintain essential physiological functions.
Basal Metabolic Rate (BMR) is the energy required for basic life processes — breathing, circulation, cellular turnover, body-temperature regulation — when the body is completely at rest in a thermoneutral environment after an overnight fast. For most adults BMR accounts for 60–75% of total daily energy expenditure. It is most commonly estimated via the Mifflin-St Jeor or Katch-McArdle equations. Factors that raise BMR include higher lean body mass, younger age, and elevated thyroid activity. Use our BMR calculator to compute yours.
Primary Sources
- Mifflin MD et al. "A new predictive equation for resting energy expenditure in healthy individuals." Am J Clin Nutr. 1990.
- Pontzer H et al. "Daily energy expenditure through the human life course." Science. 2021.