Quick Answer: Most adults burn between 50 and 80 calories per hour while sleeping, depending on body weight and basal metabolic rate. A 150 lb (68 kg) person burns roughly 63 calories per hour, or about 504 calories over an 8-hour night. Sleep quality affects how efficiently your body uses that energy.
In This Guide
Reading Time: 13 minutes
People are often surprised to learn that sleep is not a passive state. Your heart keeps beating, your lungs keep working, your brain cycles through complex activity, and your cells are busy repairing themselves. All of that costs energy. Which raises a fair question: exactly how many calories are you burning while you sleep?
The short answer is: more than most people expect, and less than a gym session. But the nuance matters, especially if you are trying to understand your total daily energy expenditure or wondering whether poor sleep is working against your health goals.
This guide walks through the science, gives you real numbers by body weight, and explains what actually drives your overnight calorie burn.
What Does Your Body Do While You Sleep?
Sleep looks calm from the outside. Internally, it is anything but.
Your body uses sleep to do the work it cannot do efficiently while you are awake. That includes cellular repair, immune system activity, hormone regulation, memory consolidation, and temperature maintenance. Every one of those processes requires energy, measured in calories.
The energy your body uses at complete rest (doing nothing but keeping you alive) is called your basal metabolic rate, or BMR. Sleep calorie burn is closely related to BMR, though not identical. Your metabolic rate dips slightly during sleep compared to waking rest, mainly because your body temperature drops and muscle activity decreases. Researchers estimate sleep metabolism runs at about 85 to 95 percent of your resting BMR.
The Science of Overnight Energy Use
A study published in the Journal of Physiological Anthropology found that core body temperature and metabolic rate follow a predictable circadian rhythm, dropping in the early hours of sleep and rising again toward morning. This is part of why your body burns calories unevenly across the night rather than at a steady rate. REM sleep stages, in particular, show metabolic activity closer to waking levels as the brain becomes highly active.
Your BMR is driven primarily by three things: your body weight, your lean muscle mass, and your age. Bigger bodies burn more calories at rest. More muscle burns more than fat at rest. And metabolism generally slows with age.
How to Calculate Calories Burned Sleeping
The most common formula used to estimate BMR is the Mifflin-St Jeor equation, which accounts for sex, weight, height, and age. From BMR, you can estimate sleep calorie burn.
Mifflin-St Jeor BMR Formula
| Sex | BMR Formula |
|---|---|
| Male | (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5 |
| Female | (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161 |
Once you have your BMR, divide by 24 to get your hourly resting calorie burn. Then multiply by 0.85 to account for the slight metabolic dip during sleep.
Sleep calories per hour = (BMR / 24) x 0.85
Multiply that hourly figure by however many hours you sleep, and you have your overnight burn estimate.
A Worked Example
Let us say you are a 35-year-old woman, 165 cm tall, weighing 68 kg.
- BMR = (10 x 68) + (6.25 x 165) - (5 x 35) - 161 = 680 + 1031.25 - 175 - 161 = 1,375 calories per day
- Hourly resting rate = 1,375 / 24 = 57.3 calories per hour
- Sleep-adjusted hourly rate = 57.3 x 0.85 = 48.7 calories per hour
- 8 hours of sleep = 48.7 x 8 = approximately 390 calories
These numbers vary person to person, but this gives a reliable ballpark.
Calories Burned by Weight: Full Chart
Rather than doing the maths yourself, here is a practical reference chart. These figures are based on Mifflin-St Jeor estimates for a middle-aged adult sleeping 7 or 8 hours, adjusted to the sleep metabolic rate of approximately 0.85 x hourly BMR.
| Body Weight | Approx. Calories/Hour Sleeping | 7-Hour Night | 8-Hour Night | 9-Hour Night |
|---|---|---|---|---|
| 120 lb (54 kg) | 38-42 | 266-294 | 304-336 | 342-378 |
| 140 lb (64 kg) | 44-50 | 308-350 | 352-400 | 396-450 |
| 150 lb (68 kg) | 48-55 | 336-385 | 384-440 | 432-495 |
| 160 lb (73 kg) | 51-58 | 357-406 | 408-464 | 459-522 |
| 180 lb (82 kg) | 57-65 | 399-455 | 456-520 | 513-585 |
| 200 lb (91 kg) | 63-72 | 441-504 | 504-576 | 567-648 |
| 220 lb (100 kg) | 69-79 | 483-553 | 552-632 | 621-711 |
| 250 lb (113 kg) | 78-89 | 546-623 | 624-712 | 702-801 |
| 280 lb (127 kg) | 87-100 | 609-700 | 696-800 | 783-900 |
These are estimates, not precise measurements. Body composition, age, hormones, and sleep quality all shift the actual figure. Think of these as reasonable guides rather than exact targets.
A Note on Ranges
The ranges above reflect the difference between male and female BMR formulas as well as variation in age (younger adults trend toward the higher end). If you want a more personalised figure, use an online BMR calculator with your specific height, weight, age, and sex, then multiply by 0.85 per hour of sleep.
Sleep Stages and Calorie Burn
Not all sleep is metabolically identical. Your body moves through distinct stages throughout the night, and each one has a slightly different energy demand.
Light Sleep (N1 and N2)
These stages dominate the early part of the night. Your heart rate slows, body temperature drops, and brain waves slow down. Metabolic rate is at its lowest here, meaning calorie burn per hour dips to roughly 80 to 85 percent of your resting rate.
Deep Sleep (N3 / Slow-Wave Sleep)
This is where the real repair happens. Growth hormone is released, tissues rebuild, and the immune system gets a significant boost. Despite all this activity, metabolic rate stays fairly low. Your body is running an efficient, targeted operation rather than a high-energy one.
REM Sleep
REM (rapid eye movement) sleep is when most vivid dreaming occurs, and your brain becomes nearly as active as when you are awake. Studies have found that brain glucose metabolism during REM is comparable to waking levels. This is when your overnight calorie burn climbs back toward its hourly peak.
REM Sleep and Metabolic Activity
Research using positron emission tomography (PET) imaging has shown that cerebral glucose utilisation during REM sleep approaches waking-state levels in many brain regions, particularly those involved in emotional memory and visual processing. This means that the brain-heavy later hours of sleep, when REM periods lengthen, contribute meaningfully to overnight calorie expenditure.
A full night of sleep cycles through 4 to 6 complete cycles, each lasting about 90 minutes. Earlier cycles have more deep sleep; later cycles have more REM. This is one reason that sleeping a full 7 to 9 hours matters beyond just feeling rested.
Factors That Affect How Many Calories You Burn Sleeping
Several things beyond body weight influence your overnight calorie burn. Some you can control; some you cannot.
Muscle Mass
Muscle tissue is metabolically active even at rest. Someone with more lean muscle mass will burn more calories per kilogram of body weight than someone with more fat tissue, even at identical body weights. This is one reason that strength training supports a higher basal metabolic rate.
Age
Metabolism naturally slows with age. This is a gradual process, not a cliff edge, but by middle age most people notice they need to eat less to maintain the same weight they had in their twenties. The BMR formulas account for this with the age variable.
Room Temperature
Your body works to maintain a core temperature of around 37 degrees Celsius regardless of the environment. Sleeping in a cold room means your body expends slightly more energy on thermoregulation. This effect is real but modest for typical indoor temperature variations. The bigger payoff of a cool room (around 15 to 19 degrees Celsius) is better sleep quality, which indirectly supports healthier metabolism.
Illness and Fever
When your immune system is fighting something, calorie burn goes up. A fever increases metabolic rate noticeably, which is part of why you feel exhausted when sick. Your body is genuinely working hard, even while at rest.
Hormones
Thyroid hormones are the primary regulators of basal metabolic rate. An underactive thyroid (hypothyroidism) will lower BMR and reduce calorie burn during sleep and at rest. An overactive thyroid does the reverse. Cortisol, growth hormone, and sex hormones also influence overnight metabolism.
Sleep Quality Itself
Here is something worth understanding: poor sleep does not necessarily mean fewer calories burned. But it does mean those calories are used less efficiently. Disrupted sleep reduces the time spent in deep and REM stages, impairing the restorative processes those stages drive. Over time, this has implications for appetite regulation, blood sugar control, and muscle recovery.
Dorothy, Sleep Specialist at Mattress Miracle: "Customers often come in thinking sleep is just rest. The research tells a different story. Your body is doing maintenance work all night. The question is whether your sleep environment lets that work happen properly. A mattress that keeps you too hot or lets you sink out of alignment is interrupting that process."
Sleep Quality and Weight Management
Calorie burn during sleep is one piece of the picture. The bigger story is how sleep quality affects your total energy balance across the entire day.
Appetite Hormones
Short sleep duration consistently increases levels of ghrelin (the hunger hormone) and reduces levels of leptin (the satiety hormone). The practical result is that people who sleep poorly tend to eat more the next day, often gravitating toward calorie-dense foods. A single night of restricted sleep can increase next-day calorie intake by 300 to 500 calories, which far outweighs any minor difference in overnight burn.
This is one of the more compelling findings in sleep research: you are unlikely to lose meaningful weight by sleeping more specifically to burn calories. But sleeping well supports the hormonal environment that makes healthy eating easier.
Insulin Sensitivity
Poor sleep impairs insulin sensitivity, meaning your cells become less responsive to insulin and less efficient at processing glucose. This is linked to weight gain over time and increases the risk of type 2 diabetes. Even partial sleep restriction over a few nights can produce measurable changes in glucose metabolism.
Exercise Recovery and Muscle Maintenance
If you exercise regularly, sleep is when your muscles rebuild. Growth hormone secretion peaks during deep sleep. Without adequate deep sleep, your recovery suffers, your workouts are less effective, and you may lose muscle mass over time, which reduces your resting metabolic rate.
What We See in Our Brantford Showroom
Many customers who come into Mattress Miracle on West Street are not just looking for a comfortable place to lie down. They are dealing with disrupted sleep that is affecting how they feel during the day, how they eat, and how they recover from physical activity. Since 1997, we have seen that the right mattress, one that keeps you properly supported and at a comfortable temperature, is often the foundation that better sleep quality is built on. A mattress that causes you to toss and turn all night is doing more than just disrupting your sleep; it is interrupting the physiological work your body needs to do.
Mattress Surface Temperature
An overheating mattress is a common culprit behind disrupted sleep. Memory foam mattresses, particularly older or denser models, can trap body heat and cause you to surface from deeper sleep stages. If you find yourself waking up at 2 or 3 a.m. feeling warm and restless, your sleep surface may be part of the problem.
Our Restonic mattress range includes models with wool and silk covers that naturally regulate temperature through the night. The Luxury Silk and Wool Queen, for example, uses zoned coils and natural fibres to create a sleep surface that stays cooler longer. If temperature is affecting your sleep quality and, by extension, your metabolic and hormonal health, it is worth considering what your mattress is made of.
You can also read our guide to optimal sleep temperature for a full breakdown of bedroom environment and sleep quality.
Practical Takeaways
What Actually Supports a Healthy Overnight Metabolism
- Sleep 7-9 hours consistently: This is where most of the benefit lies, not sleeping longer, but sleeping well across a full night.
- Keep your bedroom cool: Around 16-19 degrees Celsius supports deeper sleep and natural thermoregulation.
- Maintain muscle mass: Regular strength training raises your BMR, which means more calories burned around the clock, including during sleep.
- Limit alcohol before bed: Alcohol suppresses REM sleep and reduces deep sleep quality, lowering the restorative value of your night.
- Eat enough protein: Adequate dietary protein supports muscle maintenance, which keeps your resting metabolic rate higher.
- Address sleep disruptions: Waking frequently, overheating, or sleeping on an unsupportive surface all chip away at sleep quality and, over time, metabolic health.
If you are interested in other foods that support sleep quality, our article on whether cherries help you sleep covers the melatonin research in detail. And if late-night hunger is a pattern, see our piece on peanut butter and sleep for a practical approach to overnight blood sugar stability.
Find Your Perfect Mattress at Mattress Miracle
We are a family-owned mattress store in Brantford, helping our community sleep better since 1997. Come try mattresses in person and get honest, no-pressure advice.
441 1/2 West Street, Brantford, Ontario
Call 519-770-0001Frequently Asked Questions
How many calories do you burn sleeping for 8 hours?
Most adults burn between 380 and 640 calories over 8 hours of sleep, depending on body weight, age, sex, and muscle mass. A 150 lb person burns roughly 400-440 calories. A 220 lb person may burn 550-630 calories. These figures are estimates based on BMR calculations adjusted for the slightly lower metabolic rate during sleep.
Do you burn more calories during REM sleep?
Yes, REM sleep is metabolically more active than light or deep sleep stages, particularly in the brain. Studies using PET imaging have shown that brain glucose metabolism during REM approaches waking levels. Since REM periods become longer toward the morning, calorie burn tends to be slightly higher in the later hours of the night.
Does sleeping in a cold room burn more calories?
Slightly, yes. Your body expends energy to maintain core temperature, so a cooler room increases that workload a bit. The effect is modest at typical indoor temperatures. The more significant benefit of a cool bedroom (around 16-19 degrees Celsius) is better sleep quality, which supports healthier hormone levels and appetite regulation the next day.
Can sleeping more help you lose weight?
Not by burning more calories directly. But adequate, quality sleep supports the hormonal balance that makes healthy eating easier. Poor sleep raises ghrelin (hunger) and lowers leptin (fullness), leading to increased next-day calorie intake. Getting 7-9 hours of good sleep is one of the most underrated factors in long-term weight management.
Does a better mattress affect how many calories you burn sleeping?
Indirectly, yes. A mattress that disrupts sleep (through discomfort, pressure points, or overheating) reduces the time you spend in deep and REM sleep. Those stages drive growth hormone release, muscle repair, and optimal brain metabolism. A supportive, temperature-regulating mattress supports better sleep architecture, which supports a healthier overnight metabolism. If you are shopping in Brantford, Brad and Dorothy at Mattress Miracle can help you find the right surface for your sleep style and temperature preferences.
Sources
- Mifflin, M.D., et al. (1990). A new predictive equation for resting energy expenditure in healthy individuals. The American Journal of Clinical Nutrition, 51(2), 241-247. doi.org/10.1093/ajcn/51.2.241
- Okamoto-Mizuno, K., & Mizuno, K. (2012). Effects of thermal environment on sleep and circadian rhythm. Journal of Physiological Anthropology, 31(1), 14. doi.org/10.1186/1880-6805-31-14
- Maquet, P. (2000). Functional neuroimaging of normal human sleep by positron emission tomography. Journal of Sleep Research, 9(3), 207-231. doi.org/10.1046/j.1365-2869.2000.00214.x
- Spiegel, K., Tasali, E., Penev, P., & Van Cauter, E. (2004). Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Annals of Internal Medicine, 141(11), 846-850. doi.org/10.7326/0003-4819-141-11-200412070-00008
- Spiegel, K., Leproult, R., & Van Cauter, E. (1999). Impact of sleep debt on metabolic and endocrine function. The Lancet, 354(9188), 1435-1439. doi.org/10.1016/S0140-6736(99)01376-8
- Krauchi, K. (2007). The thermophysiological cascade leading to sleep initiation in relation to phase of entrainment. Sleep Medicine Reviews, 11(6), 439-451. doi.org/10.1016/j.smrv.2007.07.001
Visit Our Brantford Showroom
We are located at 441½ West Street in downtown Brantford. Free parking available. Our team does not work on commission, so you get honest advice based on your needs.
Mattress Miracle — 441½ West Street, Brantford, ON — (519) 770-0001
Hours: Monday–Wednesday 10am–6pm, Thursday–Friday 10am–7pm, Saturday 10am–5pm, Sunday 12pm–4pm.
If sleep quality is affecting how you feel and function during the day, we would be glad to walk you through the options. Better sleep starts with the right surface, and we have been helping Brantford families find theirs since 1997.
Shop This Topic at Mattress Miracle
Popular picks at Mattress Miracle:
- Restonic ComfortCare Dalton & Albany
- Whitney double-sided mattress
- Somnia 3.0 posture support pillow
Or explore the full mattress range in our Brantford showroom.