People tend to think of burning calories as something that only occurs during exercise, but your body is actually constantly burning calories. Your organs and cells need a constant supply of energy to function, otherwise they’d shut down and you’d quickly die.
Your body burns fewer calories when you’re sleeping for sure, but it burns calories nonetheless. On average, a person burns about 50 calories an hour while sleeping, although this figure can vary from person to person.
Here, we’ll be sharing with you everything you should know about how your body burns calories while you’re asleep.
Calories burned Sleeping Calculator
How Many Calories Do You Burn While Sleeping?
As we’ve mentioned, the average person burns about 50 calories for each hour they remain asleep. The exact number, however, depends mainly on your basal metabolic rate (BMR).
Your BMR is the number of calories your body burns simply to keep you alive. Even if you were to spend a whole day not moving a single muscle, your body would still burn some calories just to sustain itself. The number of calories you would burn in this situation is your BMR.
Your BMR is affected by a number of factors, including your weight, height, age, biological sex, diet, and exercise habits. You can calculate your BMR yourself using the following formula:
- For males, your BMR = 88.362 + (13.397 x your weight in kilos) + (4.799 x your height in centimeters) – (5.677 x your age in years)
- For females, your BMR = 447.593 + (9.247 x your weight in kilos) + (3.098 x your height in centimeters) – (4.33 x your age in years)
If this is too hard, you might want to check out this online BMR calculator that can help you simplify this process.
How Many Calories Are Burned While Sleeping vs. While Awake?
Your body will always burn more calories when you’re awake than when you’re sleeping, without question. This is still true even if you were to lie perfectly still for an entire day after waking up.
An awake body at rest burns about 15-20% more calories than a sleeping body at rest. This could be explained by the various physiological changes that occur when you enter a sleep state.
While you’re sleeping, your body temperature lowers and your heart and breathing rates slow down. Since your body isn’t working as hard to maintain its temperature and some of its other functions, it makes sense that you would burn fewer calories as a result.
Of course, the actual difference between calories burned while awake vs. while asleep is going to change depending on your BMR as well as how active you tend to be during the day.
How Many Calories Would You Burn After Sleeping for 8 Hours?
Once again, this figure is going to change considerably depending on your BMR. Assuming you’re using the 50 calories/hour figure to calculate this, you would burn 400 calories after sleeping for 8 hours.
If you want to determine exactly what your BMR is and how many calories you burn at rest, you might consider some tests done at a laboratory with a calorimeter. A calorimeter is a device that can measure how much energy you’re burning by detecting the amounts of oxygen and carbon dioxide that you inhale and exhale during breathing.
Bear in mind, however, that taking one of these calorimeter tests is a fairly expensive and complex process. Aside from having to spend a night in a lab hooked up to a calorimeter, you’ll likely have to spend 24 hours resting, 12 hours fasting, and a solid 8 hours sleeping prior to the test in order to get an accurate result.
