Basal metabolic rate (BMR) is the number of calories that the human body burns at rest, that is, the energy spent to ensure all life processes (respiration, blood circulation, etc.). BMR depends on many factors: gender, body weight, the ratio of muscle, fat, bone tissue, metabolic rate, ambient temperature, etc. The most commonly used formulas for calculating the basal metabolic rate are Harris-Benedict, Mifflin-St Jeor and Tom Venuto. The formulas use different calculation algorithms, but give approximately the same result: plus or minus 50-100 calories. First, the basic metabolism is calculated, and then coefficients are used for it, depending on the degree of load.