You burn approximately 40 to 80 calories per hour while sleeping, with an average estimate around 50 calories per hour. Over an 8-hour sleep, this typically adds up to about 400 calories burned
. The calories burned during sleep come from your body's basal metabolic rate (BMR), which supports essential functions such as breathing, circulation, brain activity, temperature regulation, and cellular repair even while unconscious
. Factors influencing calories burned during sleep include:
- Body weight and muscle mass: Heavier individuals and those with more muscle mass burn more calories during sleep because their bodies require more energy to maintain basic functions
- Sleep stages: Most calories are burned during REM sleep, when brain activity and metabolism are highest. Deep sleep and light sleep burn fewer calories but still contribute
- Body temperature: Sleeping in a cooler environment can increase calorie burn as the body works to maintain temperature
- Sleep quality and duration: Longer and better-quality sleep increases total calories burned
For a personalized estimate, you can calculate calories burned during sleep by dividing your daily BMR by 24 (hours) and multiplying by the number of hours slept, then adjusting slightly for sleep state (about 85-100% of resting metabolic rate during sleep)
. In summary, while sleeping, your body continues to burn a significant number of calories to maintain vital functions, with an average burn of roughly 400 calories during an 8-hour sleep period.
