The number of calories burned during sleep varies depending on body weight, metabolism, and the duration of sleep. On average, a person burns approximately 50-70 calories per hour while sleeping. So, if you sleep for 8 hours, you could burn around 400-560 calories. This is due to the body’s basal metabolic rate, which maintains essential functions such as breathing, circulation, and cell repair even when you’re at rest.

Calories burned during sleep contribute to why some people wake up feeling hungry. This energy expenditure, combined with the fact that you haven’t eaten for several hours, can lead to a drop in blood sugar levels, which may trigger feelings of hunger upon waking. It’s your body’s way of signaling that it needs more energy to start the day.

To maintain your weight, the total number of calories you need to burn in a day depends on your Basal Metabolic Rate (BMR) and your level of physical activity. BMR represents the calories burned at rest for essential bodily functions, which you also burn during sleep. For most adults, the BMR accounts for 60-70% of daily calorie expenditure.

To calculate the additional calories needed during the day, consider the energy spent on physical activities (e.g., walking, exercising, and other movements) and the energy used for digestion. Moderate activity typically increases total caloric needs by 25-50% above your BMR. For example, if your total daily energy expenditure (TDEE) is 2,000 calories and you burn around 500 calories during sleep, you would need to burn approximately 1,500 additional calories during the day through other activities to maintain your weight. Tools like online TDEE calculators can help estimate your exact caloric needs, taking into account factors such as weight, height, age, gender, and activity level.