How Much Sleep Do Adults Really Need?

Most adults need at least 7 hours of sleep a night, and expert groups in the US put the healthy range for adults at roughly 7 to 9 hours. Regularly getting less than 7 hours is linked to higher risks of weight gain, high blood pressure, heart disease, depression and accidents. A few people do well on slightly less or need slightly more, but true "short sleepers" are rare.

How many hours of sleep do you need at each age?

Sleep needs drop steeply through childhood and then level off. The figures below are the ranges used by the National Heart, Lung, and Blood Institute and US sleep medicine groups. For children they include naps.

Age group	Recommended sleep per 24 hours
Newborns (0 to 3 months)	Varies widely; often 14 to 17 hours
Babies (4 to 12 months)	12 to 16 hours, including naps
Toddlers (1 to 2 years)	11 to 14 hours, including naps
Preschoolers (3 to 5 years)	10 to 13 hours, including naps
School-age children (6 to 12 years)	9 to 12 hours
Teenagers (13 to 18 years)	8 to 10 hours
Adults (18 to 64 years)	7 or more hours; 7 to 9 is the usual range
Older adults (65 and over)	7 to 8 hours

Older adults do not need much less sleep than younger ones. What changes is the sleep itself: it gets lighter, people wake more often in the night, and the body clock tends to shift earlier, so many people in their 70s find themselves tired at 9 p.m. and awake at 5 a.m. The total need stays close to 7 hours.

Teenagers are the group most likely to fall short. Their body clocks shift later during puberty, which makes falling asleep before 11 p.m. hard, while school still starts early.

Why is 7 hours the cut-off for adults?

The 7-hour figure comes from a 2015 consensus statement by the American Academy of Sleep Medicine and the Sleep Research Society. A panel of experts reviewed thousands of studies and found that adults who regularly sleep less than 7 hours have higher rates of obesity, type 2 diabetes, high blood pressure, heart disease, stroke and depression. They also make more errors, have slower reactions and are more likely to be in a car crash.

Most of that evidence is observational. It shows that short sleep and poor health go together, not always that one causes the other. But lab studies, where healthy volunteers are kept to 4 to 6 hours a night for a week or two, back it up: blood sugar control worsens, appetite hormones shift toward hunger, and attention slips night after night.

One detail from those lab studies is worth knowing. People restricted to about 6 hours a night for two weeks performed nearly as badly on attention tests as people kept awake for a full night, yet they rated themselves as only slightly sleepy. Feeling fine is not a reliable sign that you are getting enough.

How do you know if you are not getting enough sleep?

The simplest test is how you feel and function during the day without propping yourself up. Common signs of too little sleep include:

• Needing an alarm every day, and hitting snooze more than once
• Falling asleep within a few minutes of lying down, or dozing off in meetings, on the couch or as a passenger
• Relying on coffee or energy drinks to get through the afternoon
• Sleeping 2 or more hours longer on days off than on workdays
• Irritability, low mood, or snapping at people more than usual
• Trouble concentrating, forgetting things, or rereading the same paragraph
• Catching colds more often

If you want a rough answer to your own number, try this on a vacation or a stretch of free days: go to bed when you are tired and wake without an alarm. The first few nights you will probably sleep long to pay back a debt. After about a week, the amount you settle at is close to what your body needs.

About a third of US adults report usually sleeping less than 7 hours, so if several of these signs sound familiar, you have plenty of company.

Can you catch up on sleep on the weekend?

Partly. Sleeping in on Saturday and Sunday does reduce sleepiness after a short week, and one or two long nights can bring alertness back toward normal. That is why the habit is so common.

The problem is what it does not fix. In a 2019 lab study, adults who slept 5 hours a night during the week and then slept as much as they liked at the weekend still showed worse insulin sensitivity, and they ate more after dinner, compared with when they slept normally. The weekend recovery did not undo the metabolic effects of the short weeknights.

Big swings between workday and weekend schedules also shift your body clock. Going to bed at 1 a.m. and waking at 10 a.m. on Sunday, then trying to sleep at 10:30 p.m. for a 6:30 alarm, is a bit like flying across three time zones every week. Researchers call this "social jet lag," and it helps explain the groggy Monday feeling.

A small catch-up of an hour or so is fine. If you regularly need much more than that, the real fix is extra sleep on weeknights, even 30 to 60 minutes earlier to bed.

Is it bad to sleep too much?

Studies that follow large groups of people find that adults who regularly sleep more than 9 or 10 hours have higher rates of heart disease, diabetes and early death. That sounds alarming, but long sleep is probably more often a sign of a problem than the cause of one.

Depression, sleep apnea, an underactive thyroid, chronic pain, heart failure and some medicines can all make people sleep longer or spend more time in bed. People who are already unwell also sleep more. Researchers cannot fully separate these effects, so nobody can say that sleeping 10 hours itself harms you.

There are good reasons to sleep longer, too. Young adults, people recovering from a stretch of poor sleep, and people fighting an infection often need more than 9 hours for a while. That is normal.

What is worth checking is a change. If you used to wake refreshed after 8 hours and now need 10 or more and still feel tired, that is a reason to talk to a doctor rather than a reason to cut back.

Does sleep quality matter as much as quantity?

Yes. Eight hours in bed is not the same as eight hours of good sleep. A healthy night cycles through light sleep, deep sleep and REM (dream) sleep four to six times. Deep sleep is when the body does much of its physical repair, and REM sleep matters for memory and mood. If those cycles keep getting broken, you can sleep a full night and still wake up unrefreshed.

Signs that quality is the issue rather than hours:

• You take more than 30 minutes to fall asleep most nights
• You wake more than once a night and struggle to get back to sleep
• You spend less than about 85 percent of your time in bed actually asleep
• Someone tells you that you snore loudly, gasp or stop breathing
• You wake with a headache or a dry mouth

Common causes of broken sleep include alcohol in the evening, a hot or noisy bedroom, needing to urinate at night, acid reflux, restless legs and sleep apnea. Regularity counts as well. Going to bed and waking at roughly the same times, within an hour or so, tends to make sleep deeper and more efficient, even when total hours stay the same.

When should you see a doctor?

Talk to a doctor if poor sleep lasts more than about three months, or affects your work, mood or relationships. Get checked sooner if you notice any of these:

• Loud snoring with pauses in breathing, choking or gasping at night, especially with high blood pressure or a larger neck size; these are signs of sleep apnea
• Falling asleep while driving, or drifting out of your lane
• Strong daytime sleepiness even after 7 to 9 hours in bed
• Sudden muscle weakness when you laugh or feel strong emotion, or vivid dreams as you fall asleep
• An urge to move your legs in the evening that stops you settling
• Low mood, loss of interest in things, or waking very early and being unable to get back to sleep
• A big change in how much you sleep without an obvious reason

Pregnant people, shift workers, and anyone taking medicines that cause drowsiness (some antidepressants, antihistamines, pain medicines or sleep aids) should ask a doctor or pharmacist before changing their sleep routine or trying a sleep supplement.

Frequently asked questions

Is 6 hours of sleep enough?

For most adults, no. Six hours a night over weeks is enough to slow reaction times and affect mood and blood sugar, even if you feel used to it. A very small number of people carry genes that let them do well on about 6 hours, but they are rare.

Do women need more sleep than men?

The official recommendation of 7 or more hours is the same for both. Women report insomnia more often, and pregnancy, periods and menopause can all disrupt sleep, so many women find they need more time in bed to get the same amount of sleep.

Does lying in bed with your eyes closed count as rest?

Quiet rest is relaxing, but it does not do what sleep does for memory, hormones and alertness. If you are lying awake for long stretches, it usually helps to get up and do something calm in dim light until you feel sleepy again.