Your body naturally burns calories through a process called the basal metabolic rate (BMR), which accounts for about 60-70% of the total calories you expend daily. BMR represents the number of calories your body needs to maintain basic life-sustaining functions such as breathing, heart beating, cell production, circulation, and maintaining body temperature while at rest

. Typically, the number of calories burned by BMR ranges roughly between 1,200 to 2,000 calories per day for most people, depending on factors like age, weight, height, sex, muscle mass, and genetics

. On an hourly basis, this is approximately 50-80 calories burned per hour at rest

. In addition to BMR, your total daily calorie burn also includes calories used during physical activity (about 20%) and digestion (about 10%)

. The total daily energy expenditure (TDEE) is the sum of BMR plus calories burned through movement and activity

. In summary:

• BMR (calories burned at rest for basic functions): ~1,200 to 2,000 calories/day
• This is about 60-70% of your total daily calorie burn
• Total daily calorie burn (TDEE) includes BMR plus activity and digestion calories
• Factors influencing BMR include age, sex, weight, height, muscle mass, and lifestyle

You can estimate your personal BMR using formulas such as the Harris-Benedict equation, which accounts for weight, height, age, and sex

. Thus, your body naturally burns roughly 1,200 to 2,000 calories per day just to keep you alive and functioning without any additional activity.