BMR
“Your Resting Metabolic Rate (RMR) is the minimum number of calories your body needs to support its basic physiological functions, including breathing, circulating blood and all of the numerous biochemical reactions required to keep you alive. Your RMR is generally 60-75% of your total daily caloric expenditure.”
“Your Basal Metabolic Rate (BMR) shows the number of calories your body needs to operate. This doesn’t account for any activity, it’s simply the energy needed to sustain a heartbeat, breathing and normal body temperature. It measures the body at rest, not sleep, at room temperature.”
See also BMI.