The amount of calories a person burns while sleeping is about 0.42 calories multiplied by the number of pounds that the person weighs multiplied by the number of hours that the person sleeps. A person who weighs 200 pounds and sleeps for eight hours per night burns 672 calories while sleeping.
Increased muscle mass and a faster metabolism allow a person to burn more calories, fat and sugar while sleeping. More calories are burned during the deeper stages of the sleep cycle, especially during REM sleep. A cooler temperature in the bedroom leads to more restful sleep and forces the body to burn more calories to produce heat.