How many calories you burn while sleeping: per hour, in 8 hours and per night
An adult burns roughly 50–75 kcal an hour asleep, about 400–600 kcal over eight hours. That is 95% of basal metabolism: sleep is barely different from complete rest. These calories are already part of your daily requirement, not something added on top.
How to calculate it for yourself
Energy burned during sleep is calculated from basal metabolic rate — the energy the body uses at rest on an empty stomach. It is estimated with the Mifflin–St Jeor equation (Mifflin and colleagues, 1990):
- men: 10 × weight in kg + 6.25 × height in cm − 5 × age + 5;
- women: 10 × weight in kg + 6.25 × height in cm − 5 × age − 161.
Metabolism during sleep is slightly below basal. In the study by Kumahara and colleagues (2004), 94 adults spent a night in a respiratory chamber, and sleeping metabolic rate averaged 95% of basal: 93% in men and 97% in women, with about 8% variation between individuals.
So: divide basal metabolic rate by 24, multiply by 0.95 and by the hours of sleep.
Calories burned while sleeping: table
Below is the calculation for four 35-year-olds: a woman 165 cm tall and a man 178 cm tall, each at two weights.
| Who | Per hour | 6 hours | 7 hours | 8 hours | 9 hours | 10 hours |
|---|---|---|---|---|---|---|
| Woman, 60 kg | 51 | 308 | 359 | 410 | 461 | 513 |
| Woman, 80 kg | 59 | 355 | 414 | 473 | 533 | 592 |
| Man, 75 kg | 67 | 402 | 469 | 536 | 603 | 670 |
| Man, 95 kg | 75 | 449 | 524 | 599 | 674 | 749 |
The heavier the person, the more they burn asleep, and the figure falls with age: every ten years the equation removes 50 kcal from daily metabolism, about 16 kcal over an eight-hour night.
There is also a rougher method based on METs, a unit of activity intensity. The 2024 Compendium of Physical Activities assigns sleep 1.0 MET (code 07030), the level of rest. By that estimate a 70 kg person burns about 70 kcal an hour asleep. It ignores sex, height and age, so for an individual the equation above is more precise.
Why sleeping more is not a way to burn more
Energy use during sleep is the lowest of the day. If you spend an hour standing in a queue instead of sleeping, the body uses more: the Compendium gives quiet standing 1.3 MET against 1.0 for sleep. The difference is a few dozen calories an hour.
Short sleep works against weight loss for another reason. In the trial by Markwald and colleagues (2013), 16 adults slept no more than five hours a night for five days. Their daily energy expenditure rose by about 5%, but they started eating more than that, especially in the evening after dinner. Over five days participants gained an average of 0.82 kg.
More on how sleep is linked to appetite and weight in the article on sleep and weight.
Where these calories sit in your daily requirement
Daily calorie calculators start from the same basal metabolism and multiply it by an activity factor. Sleep is already inside that number: eight hours of sleep is about a third of basal metabolism. There is no need to add "calories burned overnight" to your target or your diary, otherwise the same calories are counted twice.
How to find out what you actually burn rather than what the equation says is covered in the article on checking your daily expenditure. Energy used on chores and walks is in the article on calories burned in everyday activities.
When energy use during sleep may differ
The equation gives an estimate for a healthy adult. Expenditure can be lower or higher than expected with thyroid disease, fever, after surgery, and on medicines that affect metabolism. If your weight changes for no clear reason, that is a reason to see a doctor, not to recalculate your target.
Frequently asked questions
- How many calories do you burn sleeping for 8 hours?
- For most adults, 400 to 600 kcal. A 35-year-old woman weighing 60 kg and 165 cm tall burns about 410 kcal; a man of the same age weighing 75 kg and 178 cm tall burns about 540 kcal.
- How many calories do you burn sleeping for 1 hour?
- About 50–75 kcal. More precisely: divide basal metabolic rate from the Mifflin–St Jeor equation by 24 and multiply by 0.95 — metabolism during sleep is on average 5% below basal.
- Can you lose weight by sleeping more?
- Not through extra expenditure: the body uses the least energy of the day while asleep. But short sleep gets in the way of weight loss. In the trial by Markwald and colleagues, people sleeping five hours ate more than their extra expenditure and gained an average of 0.82 kg in five days.
- Should I add calories burned during sleep to my daily target?
- No. The daily target is calculated from basal metabolism, and sleep is already included. Adding it again would count the same calories twice.
- Why do you burn fewer calories asleep than awake at rest?
- That is what respiratory chamber measurements show. In the study by Kumahara and colleagues of 94 adults, sleeping metabolic rate averaged 95% of basal: 93% in men and 97% in women.
Read next
- How sleep loss affects appetite and weight — Sleep usually turns up in the last paragraph of a weight-loss article, phrased vaguely enough to be safe.
- TDEE: how the calculator works out daily expenditure and how to check your number — TDEE (total daily energy expenditure) is everything the body burns in a day: basal metabolism, digesting food and all movement.
- Daily calorie intake — There is no universal norm: it depends on weight, height, age, sex, and activity level.
This article is for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.
Figures from regulations, guidelines and studies are given as they stood when this article was prepared and may since have changed; check them against the primary sources. This article is not advertising, an offer, or individual advice, and neither the author nor the site owner is responsible for decisions taken on the basis of it.