The short answer
Most adults need 7 to 9 hours a night, and people over 65 need 7 to 8. Children need more: 9 to 11 hours at primary school age and 8 to 10 for teenagers. Large studies link regularly sleeping under about 6 hours with worse health, and long sleep, often 9 hours or more, is also linked with illness, though partly because illness causes it.
On this page
Hours by age
- Newborns0–3 months
- Babies4–11 months
- Toddlers1–2 years
- Pre-school3–5 years
- School age6–13 years
- Teenagers14–17 years
- Young adults18–25 years
- Adults26–64 years
- Older adults65 and over
Where do the figures come from?
The most widely used ranges come from an expert panel convened by the US National Sleep Foundation in 2015. Eighteen experts from sleep medicine and related fields reviewed more than 300 studies on how sleep length relates to health, mood and performance, then voted on ranges for each age group. They gave two ranges: hours that are recommended, and a wider band that may be appropriate for some people. The NHS uses the same figures: 7 to 9 hours for adults, 9 to 13 for children and 12 to 17 for toddlers and babies.
The chart above shows both ranges. These are consensus figures, not precise measurements, and they describe a typical person. Your own need may sit at either end.
What happens if you sleep too little?
The short-term effects are well proven by lab trials. In one, 48 healthy adults were assigned to 4, 6 or 8 hours in bed for two weeks. Those on 6 hours got steadily worse at attention and memory tasks, ending up as impaired as people kept awake for a whole night. The striking part: they rated themselves only slightly sleepy. People who regularly short themselves on sleep tend to underestimate how much it affects them.
Long-term, large studies link short sleep with heart disease, high blood pressure, type 2 diabetes, weight gain and depression. A review of 16 studies with more than 1.3 million people found that short sleepers were 12% more likely to die during follow-up than people who slept 7 to 8 hours. Those studies can’t fully separate cause from effect, but lab trials show plausible ways sleep loss could do harm, such as raising appetite hormones and blood pressure. See why sleep matters.
Can you sleep too much?
The same review found that long sleepers, usually 9 hours or more, had a 30% higher risk of death. But long sleep is often a sign rather than a cause: depression, heart disease, sleep apnoea, low activity and some medicines all make people sleep longer. There’s no good evidence that cutting back from 9 hours to 8 improves health. If you need much more sleep than you used to, that is worth mentioning to your GP.
Is quality as important as quantity?
Yes. Eight hours of broken sleep can leave you more tired than seven hours of solid sleep. The same foundation’s experts later agreed on signs of good-quality sleep in adults:
- falling asleep within about 30 minutes,
- waking no more than once a night for more than 5 minutes,
- being awake for 20 minutes or less in total after first falling asleep,
- spending at least 85% of your time in bed asleep.
If you regularly fall well short of these, see how to sleep better, and if it has gone on for three months or more, read about insomnia.
Do some people really need very little sleep?
A very small number of people carry rare gene variants that let them feel fine on 4 to 6 hours. They are far rarer than people who believe they are short sleepers. Most people who say they get by on 5 or 6 hours are carrying a sleep debt they no longer notice.
Keep reading
- Larks and owls: are you a morning or evening person?
What chronotype means, why some people are naturally night owls, how it changes with age and whether being an evening person is bad for your health.
- Sleep as you get older: what changes and what isn't normal
How sleep changes with age, why older people wake more and sleep less deeply, how much over-65s need, and which problems are not just down to age.
- The stages of sleep: what happens in light, deep and REM sleep
The four stages of sleep, how a typical night cycles through them, what deep sleep and REM sleep are for, and how sleep trackers measure them.
Common questions
Is 6 hours of sleep enough?
For most adults, no. In a lab study, people limited to 6 hours a night for two weeks performed steadily worse on attention tests, ending up as impaired as people who had missed a full night's sleep, while rating themselves only slightly sleepy. A few people genuinely need less sleep, but they are rare.
Is it bad to sleep 10 hours?
Long sleep is linked with heart disease and earlier death in large studies, but much of that is probably because people who are ill, depressed or inactive sleep longer. If you regularly need much more sleep than you used to, or still feel tired after long nights, see your GP.
Can you catch up on sleep at the weekend?
Partly. A lie-in pays back some of the tiredness, but it shifts your body clock later, making Sunday night and Monday morning harder. It is better to get enough sleep most nights.
How do I know if I'm getting enough sleep?
If you fall asleep within about 30 minutes, wake without great difficulty and stay alert through the day without relying on caffeine, you're probably getting enough. Nodding off when you sit still in the afternoon, or needing a long lie-in every weekend, suggests you aren't.
References
- Hirshkowitz M et al. National Sleep Foundation's sleep time duration recommendations: methodology and results summary. Sleep Health, 2015.pubmed.ncbi.nlm.nih.gov
- NHS. Insomnia (how much sleep you need).nhs.uk
- Cappuccio FP et al. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep, 2010.pubmed.ncbi.nlm.nih.gov
- Van Dongen HP et al. The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep, 2003.pubmed.ncbi.nlm.nih.gov
- Ohayon M et al. National Sleep Foundation's sleep quality recommendations: first report. Sleep Health, 2017.pubmed.ncbi.nlm.nih.gov
First published 4 November 2026. Spotted an error? Tell us and we'll correct it. Read our editorial policy.