How many hours of sleep do adults need?
Most adults need about 7 to 9 hours of sleep a night. The NHS gives that range. The US National Heart, Lung, and Blood Institute (NHLBI) lists 7 to 8 hours for adults.
The two ranges overlap, so 7 to 8 hours is a safe place to start. Some people do best near 9.
Children and teens need more, and the table below shows how the need changes with age.
| Age group | Hours of sleep a day |
|---|---|
| Babies, 4 to 12 months | 12 to 16, including naps |
| Toddlers, 1 to 2 years | 11 to 14, including naps |
| Children, 3 to 5 years | 10 to 13, including naps |
| Children, 6 to 12 years | 9 to 12 |
| Teens, 13 to 18 years | 8 to 10 |
| Adults, 18 and over | 7 to 8 (the NHS says 7 to 9) |
Adults
If you are between 18 and 65, aim for at least 7 hours on most nights. Fewer than that, night after night, is where problems tend to start.
Plan your bedtime backward from your wake time so the window is long enough.
Teens and children
Growing bodies and busy brains need extra rest. Teens are often short on sleep because of early school starts and late-night screens.
If you are a parent, treat bedtime as a fixed part of the day, not an afterthought.
Older adults
Health bodies do not usually give older adults a much lower number. Sleep can become lighter and more broken with age, but the need for rest does not disappear.
If you sleep far less than you used to and feel worse for it, mention it to your doctor.
Signs you are getting enough sleep, and signs you are not
The number on a chart is only a guide. How you feel during the day tells you more.
The NHS says you probably do not get enough sleep if you are constantly tired during the day.
You are probably sleeping enough if you
- Fall asleep within about 20 to 30 minutes of going to bed.
- Wake up without a struggle, or with only a short groggy spell.
- Feel alert through the morning and afternoon.
- Can stay awake in a quiet meeting or on a short train ride.
- Wake at about the same time on most days, even without an alarm.
You may be short on sleep if you
- Need several alarms or snooze presses to get up.
- Rely on caffeine to get through the morning.
- Feel foggy, forgetful or short-tempered.
- Fall asleep the moment your head touches the pillow.
- Sleep much longer on days off than on workdays.
Falling asleep almost instantly can sound like a good sign. It often means your body is running on empty.
Why your ideal number may differ from a friend's
The NHS notes that everyone needs different amounts of sleep. Two healthy adults can differ by an hour or more.
Several things can shift your own number.
- Age. Younger people need more, as the table shows.
- Activity. Many people find they want more rest after hard training or a physical week.
- Stress. A busy or worried mind can make sleep lighter and less refreshing.
- Health. Illness, pain and some medicines change how much rest you need.
- Body clock. Some people are natural early birds, and others peak later in the day.
So treat 7 to 9 hours as a range to work inside, not a score to hit exactly.
How to find your own sleep number
This is an informal self-check, not a medical test. It works best over one or two calm weeks with no travel or late events.
- Pick a wake time you can keep every day, including weekends.
- Go to bed only when you feel sleepy, but no later than 7.5 hours before your wake time to start.
- Write down your bedtime and how alert you feel at midday and in the evening.
- If you feel tired all day, move bedtime 15 minutes earlier and repeat for several days.
- Stop when you wake easily and stay alert. That total is your working number.
Remember that you rarely fall asleep the second you lie down. Leave a little extra time in bed on top of your target.
One short night will not harm you. What matters is the pattern over weeks, so a few off nights are nothing to worry about.
Want the whole sleep plan in one place?
Our Better Sleep Guide brings schedule, bedroom, evening routine and stress together, step by step.
Can you catch up on lost sleep?
Only partly. The NHLBI calls the total sleep you lose your sleep debt.
Lose 2 hours a night and you have a debt of 14 hours after one week.
What the NHLBI says about naps and lie-ins
Naps can give a short boost in alertness. But the NHLBI says they do not supply all the benefits of night sleep, so you cannot fully make up for lost sleep that way.
Sleeping much longer on days off can be a sign you are not getting enough during the week. It can also upset your body's sleep and wake rhythm.
A better plan than the weekend lie-in
- Move your bedtime earlier by 15 minutes at a time.
- Keep your wake time within about an hour, even on days off.
- Take a short nap earlier in the day if you need one, not late in the afternoon.
Poor sleep is not a small matter over time. The NHLBI links long-term sleep deficiency with heart disease, high blood pressure, diabetes, stroke, obesity and depression.
Those are links found in research, not a promise that a few short nights will cause them.
Plan a rest day that truly restores youDo the hours matter more than sleep quality?
Both count. Seven hours of broken sleep can leave you more tired than six hours of deep, steady sleep.
Timing counts too. Going to bed and waking at the same time helps your body clock know when to feel sleepy.
Common things that break up sleep include noise, light, a room that is too warm, late caffeine and alcohol.
Alcohol may make you drowsy at first, but it tends to disturb sleep later in the night. The NHS lists it among the things that can hurt your sleep.
Habits that help you reach your number
Knowing your target helps. These habits make it easier to hit it.
Keep a steady schedule
Choose one wake time and stick to it. Your bedtime will settle around it within a couple of weeks.
Wind down before bed
The NHS suggests a calm bedtime routine and avoiding phones, tablets and computers for an hour before bed.
Try reading, breathing exercises or gentle stretching instead.
Watch caffeine, alcohol and big meals
The NHS advises avoiding tea, coffee, alcohol and nicotine for several hours before bed. Its insomnia page gives a guide of at least 6 hours.
Large meals close to bedtime can also make it harder to drop off.
Move your body, but not too late
Regular activity tends to help sleep. The NHS suggests avoiding hard exercise in the few hours before bed.
See our Fitness hub for ways to build a routine that fits your day.
Make the bedroom work for you
Aim for a room that is dark, quiet and comfortably cool. Use blackout curtains or an eye mask if streetlight gets in.
Reset your bedroom in one evening Build a 30-minute wind-down that sticksCommon mistakes when chasing more sleep
- Going to bed too early. Lying awake for an hour teaches your brain that bed is for worrying.
- Sleeping in to fix a bad night. The NHS advises sticking to your regular hours instead.
- Checking the clock. Watching the time can raise stress and make sleep harder.
- Judging sleep by one night. Look at how you feel across a full week.
- Copying someone else's number. Your best sleep may be an hour more or less than a friend's.
- Ignoring stress. A racing mind at night usually needs a plan, not just an earlier bedtime.
If stress is the main thing keeping you up, read our five sleep-quality habits, including what to do when you cannot sleep. Our Mental Wellbeing hub also has calming ideas.
When to see a doctor about your sleep
Most sleep trouble comes from habits, stress or a busy schedule. But sometimes it points to a health issue that needs a professional.
Speak to a doctor if any of these apply.
- You have trouble falling or staying asleep for several weeks, and it affects your daytime life.
- You sleep more than 8 hours a night but still do not feel rested. The NHLBI says this may point to a sleep disorder or another health problem.
- You snore loudly, or someone sees you stop breathing or gasp during sleep.
- You feel so sleepy in the day that you nod off while working, reading or driving.
- You feel low, anxious or hopeless for a long time along with poor sleep.
If sleep trouble keeps returning, do not rely on tips alone. Ask a doctor or pharmacist before you use sleeping aids or supplements. Never drive if you feel very sleepy.
Recap: your sleep plan in five points
- Most adults need about 7 to 9 hours. Teens need about 8 to 10.
- Your best number is the one that leaves you alert all day.
- Find it with a fixed wake time and a calm week or two.
- Lost sleep adds up, and lie-ins only partly repay it.
- See a doctor if sleep problems last or you feel unwell in the day.
Hours of sleep: frequently asked questions
Most adults need about 7 to 9 hours of sleep a night. The NHS gives 7 to 9 hours, and the US National Heart, Lung, and Blood Institute lists 7 to 8 hours. The best number for you is the one that leaves you alert all day.
For most adults, 6 hours is below the usual 7 to 9 hour range. Some people feel fine on less, but many underestimate how tired they are. If you regularly sleep 6 hours or less and feel foggy, try moving bedtime earlier in small steps.
No. Eight hours is a handy average, not a rule. Some adults feel best on 7 hours and others need closer to 9. Judge your number by how alert you feel through the day.
Only partly. The NHLBI says extra sleep on days off may help you feel better, but it can upset your body's sleep and wake rhythm. A steady wake time and slightly earlier bedtimes work better than a big lie-in.
Teens aged 13 to 18 need about 8 to 10 hours a night, according to the NHLBI. Early school starts and late screen use often leave them short, so a steady bedtime and a screen-free hour before bed can help.
Sleeping a lot now and then is normal, for example when you are ill or catching up. But the NHLBI advises talking to a doctor if you sleep more than 8 hours a night and still do not feel rested, because it may point to a sleep disorder or another health problem.
Sources and further reading
We checked sleep ranges and health claims against these sources. Guidance differs slightly between organisations, so we show both the NHS and NHLBI ranges.
- NHLBI (US National Institutes of Health): How much sleep is enough?
- NHLBI: Sleep deprivation and deficiency
- NHS: Insomnia
- NHS Every Mind Matters: How to fall asleep faster and sleep better
- Sleep Foundation: Sleep hygiene
Want more? Head back to the Sleep & Recovery hub or read the Better Sleep Guide.
