Sleeping gives you a much-needed break from life's hassles. But even while you've unplugged from the chaos, your body is still busy. Your brain, heart, lungs, and other organs have to work to keep you alive. As they carry out their respective functions, they use up energy.
How many calories do you burn while sleeping, exactly? The average person burns 40 to 70 calories per hour of sleep. If they sleep for eight hours, they could burn roughly 320 to 560 calories.
The exact number depends on factors such as your body weight and metabolic rate. In this article, you'll find out how sleeping burns calories and what affects your overall calorie expenditure during sleep.
On average, you may burn approximately 0.45 calories per pound of body weight when you sleep. However, this estimate isn't used everywhere.
Older medical literature (we're talking a century-old nursing textbook revised in 1922) estimates that the body burns 0.42 calories per pound of body weight. So if you check sources relying on older numbers, you may find this smaller estimate.
However, modern sources such as the 2024 Compendium of Physical Activities, which Cleveland Clinic uses, say that the energy cost of sleeping is 1 MET. 1 MET is equivalent to 0.45 calories per pound of body weight, which is the number we're relying on for this article.
Another interesting thing is that the average resting metabolic rate (i.e., the amount of energy your body burns when you're not doing anything) is also roughly 0.45 kcal per lb of body weight. This means the number of calories burned during sleep is roughly the same as what you burn when you're doing nothing. It also means that a person with a higher resting metabolic rate (RMR) will generally burn more calories than someone with a lower RMR.
You can. Your basal metabolic rate (BMR) is the approximate number of calories your body burns over 24 hours to complete basic tasks like breathing and blood circulation. It’s similar to the RMR, but is measured under much stricter conditions.
Before going for your BMR measurement, you'll typically have to:
Then, you'll lie in a temperature-controlled setting while a trained professional records how much oxygen you breathe in and how much carbon dioxide you breathe out. Because of the complexities involved in measuring it, BMR is rarely taken outside clinical or research settings.
How many calories you burn while sleeping depends largely on how much energy your body uses when you're doing nothing. Many of the factors don't directly affect your total calorie expenditure during sleep, but they can influence your RMR.
From the RMR formula, you probably already figured out that your weight is one of the main factors affecting your calorie burn. A person who weighs more generally burns more calories during the same number of hours than someone who weighs less.
Body composition, which is what your body weight is made up of, also plays a part. Generally, body composition is divided into two: fat and everything else that isn't fat. Muscle tissue burns roughly three times more calories than fat. This is why two people weighing 140 lbs may not burn the same number of calories if they have different body compositions.
Because body composition affects energy expenditure so much, increasing muscle mass can contribute to a higher RMR over time.
You lose more fat-free mass, the part of your body weight that burns more calories, in old age. Your metabolic needs decrease, and as a result, you burn fewer calories while asleep.
However, the rate at which your body uses energy doesn't steadily decline with each birthday. A 2021 study in Science found that a person's RMR can remain stable from age 20 until age 60. After that, it may start to decline.
Men tend to burn slightly more calories than women in general because they usually have more fat-free mass and less body fat. This difference also extends to calories burned during sleep.
Some medical conditions can change how much energy your body uses at rest. For example, the thyroid produces the hormones that regulate how quickly your body burns calories, so a thyroid disorder can alter your RMR.
Some drugs can also affect your weight and RMR, thereby influencing the number of calories you burn when asleep.
Calorie burn may be higher during rapid-eye-movement (REM) sleep than in deep sleep, but the difference is usually small.
In a 2017 study in Metabolism, researchers discovered that the body uses more energy during REM sleep than other sleep stages, including deep sleep. An earlier 2009 study, also published in Metabolism, found that the participants involved in the experiment burned roughly 3.6% more calories in REM sleep than deep sleep.
Wondering why? One reason may be that during REM sleep, your brain becomes much more active, your eyes move rapidly beneath your eyelids, and your heart and lungs don’t settle into the same slow, steady rhythm they do during deep sleep. Keeping all of that activity going requires slightly more energy.
There isn't definite evidence that bad sleep makes your body burn more calories. But your calorie expenditure can increase on nights when you experience sleep deprivation. That's because the body needs fewer calories when asleep than when awake.
In a 2011 study by Jung and colleagues, the participants burned 7% more calories when they suffered sleep deprivation than when they slept for eight hours at night.
Please keep in mind that we aren't encouraging anyone to sacrifice good quality sleep for additional calorie burn. See a healthcare professional if you experience fragmented sleep regularly.
To an extent, yes.
We found two methods supported by scientific research: setting a comfortable bedroom temperature and increasing muscle mass.
[Photo by pixelshot on Canva.]
The best sheet sets may not ramp up your energy expenditure at night. What they can do is help you create a sleep environment that feels comfortable for your body.
If you sleep hot, you may prefer our percale sheet set. We also offer duvet covers in the same crisp, airy weave.
Go with sateen sheets instead if you like it when your bedding wraps you in a cozy embrace. They're buttery-soft and smooth, and offer a bit more insulation than percale.
A rough estimate for many adults is around 320 to 560 calories over eight hours, based on an estimated calorie burn of roughly 40 to 70 calories per hour.
The exact number depends on factors such as your body weight, muscle mass, age, sex, and resting metabolic rate.
You usually burn fewer calories sleeping than you do while awake. During waking hours, you may talk, move around, walk, work, or do other activities that require extra energy.
Your RMR can help you estimate how many calories you burn during sleep. However, it shouldn't be a reason to pressure yourself into cutting back on sleep. Note the number, see a medical professional if you have concerns, keep your sleep environment comfortable, and doze as much as you need.
