by Quick answer: Most adults burn about 40 to 70 calories per hour while asleep. Multiply that range by your time actually asleep for a sensible estimate, then treat the result as a range, not a precise total.
- Sleep Foundation reports an estimated burn of about 40 to 70 calories per hour for most sleeping adults.
- The estimate varies with body size, age, sex, and individual metabolism.
- Sleep stages affect energy use, so one hourly figure can’t describe every part of the night.
Updated July 2026 · Reviewed for accuracy
You continue using energy while you sleep, but there isn’t one universal overnight total. The useful figure is about 40 to 70 calories per hour for most adults, according to Sleep Foundation. Your sleep duration and personal characteristics decide how that hourly range translates into a nightly estimate.
The hourly answer and the honest calculation
Most adults burn roughly 40 to 70 calories for each hour of sleep. That’s the clearest answer supported by the published figure. It’s an estimate rather than a personal measurement, and the width of the range matters as much as the endpoints.
An overnight total can’t be stated until sleep duration is known. Someone who sleeps for a shorter period has fewer sleeping hours to include in the calculation, while someone who sleeps longer has more. That doesn’t tell us where either person falls within the hourly range.
| Estimate | Calculation | What it represents |
|---|---|---|
| Lower boundary | Hours actually asleep × 40 | The bottom of the reported adult range |
| Upper boundary | Hours actually asleep × 70 | The top of the reported adult range |
I’d report both results. Choosing one endpoint without a reason creates a false sense of accuracy. The lower result isn’t automatically more realistic, and the upper result isn’t a target.
Use the time you believe you were asleep, not automatically the full period between getting into bed and getting up. If you don’t know your actual sleep duration, calculate a wider range using the shortest and longest durations you consider plausible.
The Nut’s take: The honest answer is an hourly range plus your sleep duration. Any calculator that produces a sharply precise total still has to make assumptions about the personal factors that affect your result.
Why your personal estimate sits somewhere in the range
The gap between 40 and 70 calories per hour reflects real individual variation. Sleep Foundation names body size, age, sex, and metabolism as factors affecting how many calories an adult burns while asleep. Its discussion also recognizes that calorie use differs across sleep stages.
| Factor | What the source establishes | How to handle it |
|---|---|---|
| Body size | It contributes to differences between adults. | Don’t choose an endpoint from body size alone. |
| Age | The estimate varies with age. | Don’t reuse another person’s result as your own. |
| Sex | It is one of several relevant inputs. | Treat it as one factor, not a complete formula. |
| Metabolism | Individual metabolism affects the hourly result. | Keep the output as a range unless you have better personal data. |
| Sleep stage | Energy use can change across sleep stages. | Don’t interpret the hourly estimate as a constant minute-by-minute rate. |
No factor-specific adjustment is established by the broad 40-to-70 figure. Adding an arbitrary amount because of your age, body size, or sex would manufacture precision. Placing yourself automatically at the top or bottom would do the same.
Metabolism is particularly important to the limits of this calculation. Sleep Foundation lists it as a source of variation, but the hourly range doesn’t reveal an individual metabolic rate. That’s why two people with the same sleep duration shouldn’t assume they burned exactly the same amount.
Keep the estimate honest
- Use 40 and 70 as boundaries, not promises.
- Don’t select an endpoint from one personal characteristic.
- Label the final result as approximate.
The range is still useful. It gives you a defensible scale for sleeping calorie use without pretending that a general figure is a personalized measurement.
How to calculate your overnight range
The calculation needs one input from you: how long you were actually asleep. Multiply that duration by 40 for the lower boundary, then repeat the calculation with 70 for the upper boundary.
Lower overnight estimate
Hours asleep × 40 calories
Upper overnight estimate
Hours asleep × 70 calories
Final wording
“I likely used about the lower result to the upper result while sleeping.”
Suppose your sleep duration is known with reasonable confidence. Apply the same duration to both endpoints. That keeps the only changing part of the calculation tied to the published hourly range.
If your sleep duration is uncertain, don’t hide that uncertainty. Multiply your shortest plausible sleep duration by 40 for the lower boundary. Multiply your longest plausible duration by 70 for the upper boundary. The result will be wider, but it will better reflect what you actually know.
| Your information | Lower calculation | Upper calculation |
|---|---|---|
| Sleep duration is known | Known duration × 40 | Known duration × 70 |
| Sleep duration is uncertain | Shortest plausible duration × 40 | Longest plausible duration × 70 |
Keep all of your units consistent. The source figure is stated per hour, so your duration must also be expressed in hours before multiplying. Round only after completing the calculation, because repeated rounding can make a broad estimate appear more exact than it is.
I wouldn’t replace the range with its midpoint. A midpoint can look tidy, but nothing about it makes that number more personal to you. The endpoints preserve the uncertainty already built into the source figure.
A useful result sounds approximate: “Based on my estimated sleep duration and the reported adult range, I probably burned between these two totals.” That wording is more accurate than claiming one exact calorie.
Calories burned during sleep are not weight lost
The 40-to-70 figure describes estimated energy use during an hour of sleep. It doesn’t state how much body weight changed overnight. Those are different questions, and the hourly estimate alone can’t bridge the gap.
This is where the wording “lose calories” can mislead. The clearer phrasing is “use” or “burn” calories while sleeping. For a deeper explanation of that distinction, see my guide to whether you lose calories when you sleep.
What the estimate can tell you
- A broad hourly calorie range for most adults
- A lower and upper overnight estimate
- Why personal results shouldn’t be treated as identical
What it can’t tell you
- Your exact personal calorie use
- Whether your body weight changed
- Whether calories came from any particular body area
I also wouldn’t treat sleep duration as a calorie-burning target. The published range tells us approximately how much energy adults use while asleep. It doesn’t support prescribing more or less sleep as a way to chase a particular calorie total.
The same limit applies to sleeping position. The cited hourly range doesn’t assign different calorie values to the back, side, or stomach. If position is the reason behind your question, I’ve addressed sleeping position and belly-fat claims separately.
For the broader relationship between sleep and changes in body weight, read my explanation of whether sleeping helps you lose weight. Keep that question separate from the arithmetic here: this article estimates energy used during sleep, not a weight-loss result.
Why sleep stages and awake time keep this approximate
Sleep Foundation explains that calorie use varies across sleep stages. That means the body’s energy use isn’t necessarily a flat rate throughout every part of the night. The broad hourly range smooths those changes into a usable estimate.
The 40-to-70 range isn’t a stage-by-stage calculator. It doesn’t tell you how long you personally spent in each stage, and it doesn’t support assigning a separate calorie total to each segment of your night.
| Time period | Include it? | Reason |
|---|---|---|
| Time you believe you were asleep | Yes | The reported rate concerns calories used while sleeping. |
| Time awake before falling asleep | No | It isn’t sleeping time. |
| Time awake during the night | Exclude if known | The question asks specifically about sleep. |
If all you know is the full window spent in bed, you can still make a rough calculation. Label it as a bed-window estimate, though, rather than claiming every minute was sleep. That small distinction prevents a rough input from becoming a falsely precise output.
Before accepting a calorie total, check:
- Does it use the reported 40-to-70 hourly range?
- Does it count sleep time rather than automatically counting all time in bed?
- Does it present a range and acknowledge personal variation?
A tracker or calculator may display one clean total, but a precise display doesn’t remove the assumptions underneath it. Unless its inputs establish a more personal estimate, I’d retain the broader range and say exactly how it was calculated.
My bottom line
Most adults burn about 40 to 70 calories per hour while sleeping, according to Sleep Foundation. Multiply your estimated hours asleep by both endpoints. Those two results form the most defensible overnight range available from the stated data.
Use this answer: “I likely burned between my hours asleep multiplied by 40 and my hours asleep multiplied by 70.” Keep “likely” and keep the range.
I wouldn’t narrow it further from the query alone. Body size, age, sex, metabolism, and sleep stage all affect the result, but the broad hourly figure doesn’t provide a reliable personal adjustment for any one of them.
FAQ
How many calories do you burn per hour while sleeping?
Sleep Foundation reports that most adults burn about 40 to 70 calories per hour while asleep. Your position within that range can vary with body size, age, sex, metabolism, and sleep stage.
How do I calculate the calories burned over a whole night?
Multiply your actual hours asleep by 40 to find the lower boundary. Multiply the same duration by 70 for the upper boundary, then report the answer as a range.
Can I calculate sleeping calories from body weight alone?
Body size is one factor named by Sleep Foundation, but it isn’t the only one. Age, sex, metabolism, and sleep stage also matter, so body weight alone doesn’t justify choosing one exact hourly value.
Do different sleep stages change calorie use?
Yes. Sleep Foundation explains that calorie use varies across sleep stages, which is one reason the hourly number should remain approximate. The broad adult range doesn’t support a personalized stage-by-stage calculation.
Should I count all the time I spend in bed?
Count the time you believe you were actually sleeping if you want an estimate for calories burned during sleep. If you only know your full time in bed, label the result as a rough bed-window estimate rather than an exact sleeping total.