How many calories do you burn sleeping? Plus, what can affect it

Sleep

Nov 26

Written By Calm Editorial Team

image of: how many calories do you burn sleeping

Clinically reviewed by Dr. Chris Mosunic, PhD, RD, MBA

Sleeping burns more calories than you might think. Find out how to estimate how many calories you're burning at night, and what can affect those numbers.

On especially long days, you might count down the hours until you can crawl under the covers and rest. But have you ever considered what happens inside your body while you’re sleeping — and how much energy you’re actually using?

The truth is, sleep isn’t passive. Your body may be still, but it’s also working hard repairing cells, regulating hormones, consolidating memories, and keeping vital systems running smoothly. It may not feel like much is happening, but the metabolic activity is real.

So, how many calories do you actually burn while sleeping? And which factors—like body composition, sleep quality, or room temperature—can influence that number? Here’s what the research shows, and why this matters more for understanding how your body works than tracking any specific total.

How many calories do you burn while sleeping?

On average, most adults burn about 50 calories per hour while sleeping. So, say you sleep a typical eight-hour night: that means you burn roughly 400 calories while sleeping. But this number can also vary based on gender, individual weight, and metabolism.

Here are a few ways those factors can change the number of calories you burn while sleeping:

Someone weighing around 125 lbs burns about 38 calories per hour, or roughly 266–342 calories across 7–9 hours of sleep.
Someone weighing around 150 lbs might burn about 46 calories per hour, or 322–414 overnight.
Someone weighing around 185 lbs may use about 56 calories per hour, which adds up to 392–504 total.

These are simply averages, but the point is that your body continues using energy while you sleep — just at a lower rate when compared to waking activities.

What factors affect caloric burn during sleep?

Your overnight calorie burn isn’t fixed. It changes from person to person and even from night to night, depending on several factors. These might include:

Body weight and composition: Larger bodies require more energy to maintain basic functions, so more calories are automatically burned during sleep. If you have more muscle mass, this can raise your resting expenditure (and sleep expenditure) because muscle is more metabolically active than fat.
Basal metabolic rate (BMR): Your BMR is the number of calories your body needs if you were completely at rest 24/7. Sleep burns somewhat less than your awake-resting rate (approximately 15 percent fewer calories per hour while sleeping than while awake and resting).
Age and sex: Metabolism typically declines with age, and in terms of differences in sex, men tend to have higher resting energy expenditure than women on average because they typically have higher muscle mass.
Sleep stage and quality: Not all sleep is equal. During REM sleep, your brain is more active and may burn more calories than in deep (non-REM) sleep, which is when the body slows down.
Environment and other physiological factors: Room temperature can play a role in calorie burn, since cooler rooms may increase energy use while your body’s trying to keep itself warm. Other factors like hormones, health, and sleep disruptions can all influence how many calories you burn.

How to estimate how many calories you burn during sleep

If you want a rough estimate for yourself, here’s a simple method to help calculate how many calories you burn sleeping.

Estimate your basal metabolic rate (BMR) using an online calculator or offline tool (for example, the Harris–Benedict equation). This gives you your approximate calorie burn per day if you were completely at rest.
Divide your BMR by 24 to get an approximate “calories burned per hour” at rest.
Multiply that by the number of hours you usually sleep.
Optionally adjust by 85 percent (i.e., multiply by 0.85) to account for the fact that you’ll burn a little less energy while you’re sleeping than awake.

As an example, if your BMR is about 1,500 calories a day, you’d divide 1,500 by 24 and get 62.5 calories per hour. Eight hours of sleep (62.5 multiplied by 8) equals 500 calories, which you’d then multiply by 0.85 to give you an answer of roughly 425 calories burned overnight.

It’s important to note, though, that these are just ballpark figures. Small variations in body composition, hormone levels, and sleep quality can all change the number of calories you burn while sleeping. It’s better to view these numbers as a sign of your body’s quiet efficiency, and not a score to improve.

There’s no need to track, fix, or optimize your nighttime calorie count. If calorie numbers ever feel stressful, it’s completely okay to step away from them altogether.

How to improve sleep (and burn more calories while sleeping)

The most effective way to burn more calories while you sleep isn’t necessarily about sleeping more — it’s about sleeping better. Deeper, more consistent rest helps your body regulate hormones, repair muscles, and maintain a steady metabolism.

The more consistently you rest, the more efficiently your metabolism can do its work overnight. Here are some simple strategies that can help improve your sleep quality and consistency.

1. Keep a loose routine

Keeping a consistent sleep schedule—waking up and going to bed at roughly the same time each day—can help train your internal clock to wind down more naturally. Over time, this rhythm can help you fall asleep faster and stay asleep longer.

2. Dim the lights early

Exposure to bright or blue-toned light in the evening can delay melatonin release, making it harder to fall asleep. Turning off overhead lights, switching to warm lamps, or using night mode on screens in the hour before bed can send a clearer signal that it’s time to rest.

Even small changes in lighting can help your body start that transition more smoothly.

💙 Instead of reading with the lights on, press play on a soothing Sleep Story, like Behind the Velvet Curtain with Cynthia Erivo on the Calm app.

3. Cool it down

A cooler bedroom (typically between 65 and 68 degrees Fahrenheit) is ideal for high-quality rest. That drop in temperature helps your body mimic its natural nighttime cooling process, making it easier to fall and stay asleep.

It also signals to your brain that it's time to power down for the night. Adding a fan, cracking a window, or switching to breathable bedding can make a noticeable difference if your room tends to run warm.

4. Eat lightly before bed

If you’re feeling a little hungry at night, a small, nutrient-rich snack can help stabilize blood sugar without interfering with digestion. Think: yogurt with berries, a banana with a spoon of peanut butter, or a small bowl of oatmeal.

Do your best to avoid heavy or spicy meals too close to bedtime, as they can lead to indigestion, bloating, or disrupted sleep.

5. Wind down intentionally

Carving out a short period to wind down (ideally 20 to 30 minutes) can ease the mental whiplash between daytime stress and sleep. You don’t need to have a full wellness routine, but even simple habits like reading a few pages of a light book, listening to calm music, or stretching slowly can help.

What matters most is consistency. Over time, your body learns that these signals mean it’s safe to shift gears and prepare for rest.

💙 Need a little extra support winding down? Try the White Noise Soundscape on the Calm app.

6. Prioritize calm connection

Emotional stress doesn’t just live in your mind — it can show up in your sleep too. Taking a moment to check in with yourself or someone else at the end of the day can help you release tension that might otherwise keep you up.

That might mean journaling, venting about your day, or even sitting quietly with someone you feel safe with. These small acts of connection can lower cortisol levels and remind your nervous system that it’s okay to relax.

💙 Learn how to cultivate better relationships with Jay Shetty’s Curiosity Builds Connection meditation on the Calm app.

How many calories do you burn sleeping FAQs

How does rest support my metabolism?

Even while resting, your body is using energy to support essential bodily functions like breathing, circulating blood, regulating body temperature, and repairing tissues.

Sleep gives your body time to recover and regulate your hormones, especially those involved in hunger, satiety, and metabolism. In this way, sleep indirectly supports a healthy metabolic rate.

Do you burn more calories sleeping or watching TV?

You use slightly more energy while sitting awake than asleep, because your brain and body are busier.

But staying up late to watch TV can disrupt your hormones and reduce overall metabolic health, so sleep is still the better investment if you want to improve calorie burn.

How many calories do you burn in eight hours of sleep?

Most adults burn roughly 400 calories in eight hours of sleep, but people with more muscle mass or a higher metabolism may use closer to 500 calories.

If you’d like to calculate a rough idea for yourself, multiply your weight in pounds by 0.42 to estimate the number calories burned per hour. Then, multiply this number by your usual hours of sleep. While the number won’t be exact, it can help give you a brief range of how your body keeps using energy, even while you rest.

Can better sleep really help you burn more calories?

Yes, but it’s an indirect connection. Improving both sleep quality and consistency can support your metabolism, help regulate hunger and fullness hormones like ghrelin and leptin, and maintain muscle mass.

This helps support a higher basal metabolic rate (BMR), which in turn allows you to burn more calories overall, including during sleep.

Does muscle mass affect how many calories you burn while sleeping?

Yes. Having more muscle means you’ll burn more calories per hour (even while sleeping) than someone with less muscle mass, even if all the other factors like sex and weight are the same.

Is tracking calories burned during sleep worth it?

For most people, no. It might be interesting to learn as a rough benchmark, but given the many variables and uncertainties, it’s not highly accurate. It can even become distracting or counterproductive, especially if you have (or have had) disordered eating or an unhealthy focus on weight and caloric burn in the past.

Instead of focusing on calories burned while sleeping, concentrate instead on building good sleep habits, moving consistently, and nourishing your body.

Do you burn fat while sleeping?

Since you burn calories during sleep, some of that will come from fats or carbohydrates as energy sources.

But your total energy balance, muscle mass, sleep quality, and daily activity matter much more. Sleep isn’t a special trick for fat loss, but rather a way to keep your hormones and mood balanced, allowing you to have more energy during the day.

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Calm Editorial Team