The Basal Metabolic Rate (BMR) Calculator computes your BMR, which represents the energy expended while at rest in a neutral-temperature environment and during a post-absorptive state (indicating that the digestive system is inactive, requiring approximately 12 hours of fasting).

The basal metabolic rate (BMR) signifies the energy necessary for bodily functions at rest in a moderate climate when digestion is not active. It’s akin to determining the fuel consumption of a stationary car. In this state, energy is solely utilized to sustain essential organs such as the heart, brain, kidneys, nervous system, intestines, liver, lungs, reproductive organs, muscles, and skin. For most individuals, approximately 70% of daily energy expenditure is allocated to maintenance. Physical activity accounts for roughly 20% of energy expenditure, while about 10% is utilized for food digestion, termed thermogenesis.

Measuring BMR requires strict conditions during wakefulness, necessitating the absence of activity in the sympathetic nervous system, indicating complete rest. Basal metabolism typically constitutes the largest portion of an individual’s total calorie requirements. Daily calorie needs are determined by multiplying the BMR value by a factor ranging from 1.2 to 1.9, depending on activity levels.