How much sleep do adults need? The official answer by age
How much sleep adults need at every age, according to the CDC, NHS and sleep scientists, plus what the research says about six hours, lie-ins and long sleep.
Why it matters
Most official health advice treats 7 hours as the minimum for adults, and many people who think they reach it sleep less than they believe.
Adults need at least 7 hours of sleep a night, according to the US Centers for Disease Control and Prevention (CDC) and the two main American sleep science bodies. More than a third of American adults regularly get less, and the true share is probably higher than surveys show.
Quick answer: Adults aged 18 to 60 should sleep 7 or more hours a night on a regular basis, the CDC and the American Academy of Sleep Medicine (AASM) say. The UK’s National Health Service (NHS) puts the average adult need at 7 to 9 hours. From age 65, the CDC’s range is 7 to 8 hours.
That 7-hour figure is a floor, not a target. Nobody official tells adults to aim for exactly 8 hours, and the guidance allows for real differences between people.
The question is timely this week. Clocks in the UK and most of Europe went back an hour on Sunday 25 October 2026, and most of the United States follows on Sunday 1 November. Both shifts nudge the body clock, and sleep doctors have firm views on them, covered at the end of this piece.
The official numbers, side by side
Health bodies agree on the minimum and differ slightly at the top of the range.
| Age | CDC (US) | National Sleep Foundation (US) | NHS (UK) |
|---|---|---|---|
| 18 to 60 | 7 or more hours | 7 to 9 hours | 7 to 9 hours |
| 61 to 64 | 7 to 9 hours | 7 to 9 hours | 7 to 9 hours |
| 65 and older | 7 to 8 hours | 7 to 8 hours | 7 to 9 hours |
Source: CDC, About Sleep (May 2024); National Sleep Foundation (June 2026); NHS, Insomnia (reviewed March 2024). The NHS gives one figure for all adults.
These are averages for healthy people without a sleep disorder. The National Sleep Foundation (NSF) says an extra hour or two on either side of its range may suit some individuals, which is a wider band than most people assume.
Where the 7-hour minimum comes from
Two expert reviews published in 2015 sit behind almost every figure you will see. The CDC cites both on its own sleep pages.
The first was a joint consensus statement from the AASM and the Sleep Research Society, published in the journal Sleep. A panel of 15 sleep specialists and researchers worked through 5,314 scientific papers and then voted on how much sleep is linked to the best health in adults. Their wording was deliberately plain: adults should sleep “7 or more hours per night on a regular basis to promote optimal health.”
The words “on a regular basis” matter. The panel was describing a habit across weeks and months, not a rule that one 6-hour night undoes. It also added a caveat that tends to get lost: sleeping more than 9 hours a night may be appropriate for young adults, for people recovering from a sleep debt and for people who are ill.
The second review came from the NSF, which convened an 18-member panel drawn from 12 medical and scientific organizations. It set 7 to 9 hours as the recommended range for adults up to 64, and 7 to 8 hours for those 65 and older. The CDC’s figures for people over 60 come from this report.
The NHS figure of 7 to 9 hours matches the NSF range. The NHS adds that everyone needs different amounts.
Is 6 hours of sleep enough?
For most adults, the official answer is no. Six hours falls below the floor set by the CDC and the AASM.
The AASM panel linked regularly sleeping less than 7 hours with weight gain and obesity, diabetes, high blood pressure, heart disease and stroke, depression and a higher risk of death. It also tied short sleep to weaker immune function, more pain, worse performance, more errors and a greater risk of accidents.
Most of that evidence comes from observational studies, which follow large groups of people and compare outcomes. They show that short sleep and these problems tend to travel together. On their own they cannot prove that short sleep caused the problem in each case, because the same people may also differ in work hours, stress, income or existing illness.
The largest pooled analysis of sleep and death rates was published in Sleep in 2010 by a team led by Francesco Cappuccio at the University of Warwick in England. It combined 16 studies covering 1,382,999 people, followed for 4 to 25 years, during which 112,566 died. People in the short-sleep groups had a 12% higher risk of dying during follow-up than those in the reference groups, which mostly slept about 7 hours.
The detail behind that 12% is untidy, and the authors said so. The 16 studies defined short sleep in different ways, from 4 hours or less to anything under 7. Sleep was self-reported, usually once, at the start. The pattern was still consistent enough for the team to suggest that people who regularly sleep 5 hours or less should be treated as a higher-risk group.
Are some people genuinely fine on six hours?
A few are, and the reason appears to be genetic.
In 2009 a team led by neurologist Ying-Hui Fu at the University of California, San Francisco reported in the journal Science that a mother and her adult daughter carried a mutation in a gene called DEC2. Both had needed roughly 6 hours a night all their lives and felt fine on it. When the researchers engineered mice to carry the same mutation, the mice also slept less, and they made up less lost sleep after being kept awake.
Fu’s group has since found other short-sleep mutations, but they are rare. The UCSF researchers described the DEC2 change as one that “may be rare” when they announced it. That is the catch for anyone hoping to be a natural short sleeper. The carriers studied so far were found by searching for families who thrive on little sleep, and the variants explain only a small share of people who sleep 6 hours.
Why the surveys probably flatter us
Almost every national figure on sleep, including the CDC’s, comes from people estimating their own sleep. That method has a known bias.
In the CARDIA Sleep Study, published in the journal Epidemiology in 2008, Diane Lauderdale of the University of Chicago and colleagues gave 669 middle-aged adults in Chicago wrist monitors that track movement, a standard way to measure sleep at home, and also asked them how long they usually slept. Measured sleep averaged about 6 hours a night. Reported sleep averaged about 6.8 hours. The gap was largest among the shortest sleepers: people who actually slept around 5 hours over-reported by more than an hour.
Two consequences follow. First, if the Chicago pattern holds more widely, national surveys understate how many adults sleep under 7 hours. Second, a person who believes they sleep “about 7 hours” may be getting noticeably less.
Key figure: In a CDC analysis of 444,306 US adults surveyed in 2014, 65.2% said they usually slept at least 7 hours in 24 hours. The rest, just over a third, fell short by their own account.
Later data from the same CDC survey, the Behavioral Risk Factor Surveillance System, show no improvement. The share of adults reporting less than 7 hours was the same in 2022 as in 2013. In 2022 it ranged from 30% in Vermont to 46% in Hawaii. Among the groups the CDC reports, men (37%) and adults aged 45 to 64 (39%) had the highest rates.
Can a weekend lie-in pay back the debt?
The best controlled test so far suggests it does not, at least for metabolism.
In a study published in Current Biology in February 2019, Christopher Depner and Kenneth Wright of the University of Colorado Boulder kept 36 healthy adults aged 18 to 39 in a clinical research unit for two weeks, where their sleep, light and food were monitored. One group could sleep 9 hours a night. A second was limited to 5 hours. A third was limited to 5 hours on weekdays, allowed to sleep as long as it liked over a weekend, and then restricted again.
Both restricted groups snacked more after dinner, gained weight and became less sensitive to insulin, an early marker of diabetes risk. In the group restricted all the way through, whole-body insulin sensitivity fell by about 13%. The weekend group did not escape: its sensitivity fell by 9% to 27% depending on the measure, with the liver and muscles faring worst. On average the weekend sleepers gained only about 66 minutes of extra sleep, and the small benefits of the lie-in disappeared once the short nights resumed.
The study was small and lasted two weeks, so it cannot say what years of the pattern do. Its lesson, in Wright’s words to his university’s news service, was that “Consistency matters.”
Can you sleep too much?
Possibly, though here the evidence is weakest.
In the 2010 Warwick analysis, long sleepers had a 30% higher risk of death than the reference groups, a bigger figure than for short sleep. Read quickly, that sounds like a warning against long nights. The authors read it differently. They noted that no one had shown how long sleep could cause harm, and suggested that sleeping 9 hours or more is more likely a sign of illness already present, possibly undiagnosed, than a cause.
The AASM takes a similar line. For adults outside the groups who may need more, its panel said it was uncertain whether sleeping over 9 hours carries any health risk.
That is why the AASM’s advice to talk to a healthcare provider covers sleeping too much as well as too little.
Signs your sleep is not doing its job
The CDC says quality matters alongside hours, and defines quality sleep as uninterrupted and refreshing.
Watch for: The CDC lists trouble falling asleep, waking up repeatedly during the night and feeling tired even after enough sleep as signs of poor-quality sleep. The NHS says you are probably not getting enough sleep if you are constantly tired during the day.
The CDC’s suggested habits for better sleep are:
- Keep a schedule: go to bed and get up at the same time every day.
- Set up the room: keep the bedroom quiet, relaxing and cool.
- Switch off screens: turn off electronic devices at least 30 minutes before bed.
- Watch late meals: avoid large meals and alcohol before bedtime, and limit caffeine in the afternoon and evening.
- Stay active: exercise regularly and eat a healthy diet.
What to do: The NHS says to see a GP (family doctor) if changing your sleep habits has not helped, if you have had trouble sleeping for months, or if poor sleep is making daily life hard to cope with. The AASM also advises anyone worried that they sleep too little or too much to talk to a healthcare provider.
Why sleep doctors want the clock changes to stop
In October 2023 the AASM published a position statement in the Journal of Clinical Sleep Medicine calling on the United States to “eliminate seasonal time changes in favor of permanent standard time.” Its argument is that standard time fits human circadian biology best, and that the switch to and from daylight saving time carries health and safety risks.
That puts the doctors at odds with the Sunshine Protection Act, a long-running bill in Congress that would make daylight saving time permanent instead. A version passed the Senate in 2022 and stalled in the House. The European Union voted in 2019 to end seasonal changes, but the change has never taken effect.
Until something changes, the timetable stays as it is:
- 25 Oct 2026: Clocks in the UK and the European Union go back one hour.
- 1 Nov 2026: Daylight saving time ends at 2 a.m. local time in most of the United States. Hawaii and most of Arizona do not change.
- 14 Mar 2027: US clocks go forward again.
- 28 Mar 2027: UK and EU clocks go forward.
How to read the next sleep headline
New sleep studies appear almost weekly, and three questions sort the strong ones from the weak. Was sleep measured with a device, or did people estimate it? Who was the comparison group, and how many hours did they sleep? And for any finding about long sleep, did the researchers account for illness that was already there?
Keep one number in mind while reading them: 7 hours, measured, most nights. Everything official on adult sleep is built on that floor.
This article is for information only and is not medical advice. Speak to a doctor or other health professional about your own sleep.
