Most adults need at least 7 hours of sleep per night. That’s the baseline recommendation from both the CDC and the American Academy of Sleep Medicine, and it applies to anyone between 18 and 60. Children and teens need significantly more, and the specific number shifts at nearly every stage of life.
Recommended Sleep by Age
Sleep needs are highest at birth and decline steadily through childhood. Here are the current guidelines, based on NIH recommendations:
- Newborns (0 to 3 months): 14 to 17 hours
- Infants (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
- Teens (13 to 18 years): 8 to 10 hours
- Adults (18 to 60 years): 7 or more hours
- Older adults (61 to 64 years): 7 to 9 hours
- Adults 65 and older: 7 to 8 hours
For children under 5, these totals include naps, not just nighttime sleep. A toddler sleeping 10 hours at night and napping for 2 hours is well within range. By school age, most children have dropped naps entirely, so the full amount comes from overnight sleep.
Notice that older adults don’t need dramatically less sleep than younger adults. The range narrows slightly (7 to 8 hours instead of 7-plus), but the floor stays the same. What changes with age is the ability to get that sleep in one uninterrupted stretch, not the actual need for it.
What Happens Below 7 Hours
The 7-hour threshold isn’t arbitrary. Consistently sleeping less than that is linked to higher rates of obesity, type 2 diabetes, high blood pressure, heart disease, stroke, anxiety, and depression. The CDC estimates that roughly 83.6 million American adults fall below this cutoff.
Cognitive effects show up even earlier in the decline. Harvard Health reports that sleeping 6 hours or less per night is associated with measurable impairment in memory and an increase in a brain protein called amyloid-beta, which is a hallmark of Alzheimer’s disease. In practical terms, this means that functioning on 5 or 6 hours, even if it feels manageable, carries costs your brain is quietly accumulating.
The damage from short sleep isn’t limited to extreme deprivation. You don’t need to pull an all-nighter to feel the effects. Shaving even an hour off your sleep on a regular basis can shift your risk profile for chronic disease over time.
Too Much Sleep Carries Risks Too
While most public health messaging focuses on getting enough sleep, consistently sleeping too long is also associated with poorer health outcomes. A large meta-analysis combining data from multiple studies found that long sleepers had a 39% higher risk of mortality, a 46% higher risk of stroke, a 26% higher risk of developing diabetes, and a 25% higher risk of cardiovascular disease compared to people sleeping a normal amount.
This doesn’t mean that one lazy Sunday morning is dangerous. These associations apply to habitual long sleep, typically defined as 9 or more hours per night for adults on a regular basis. And the relationship appears to be linear: the longer the habitual sleep beyond that range, the stronger the association with cardiovascular disease and mortality.
Importantly, long sleep itself may not always be the cause. It can be a signal of underlying conditions like depression, chronic pain, or sleep disorders that fragment rest and make you need more total time in bed to feel restored. If you consistently need 10 or more hours and still wake up tired, the issue is likely sleep quality rather than quantity.
Sleep Needs During Pregnancy
Pregnancy doesn’t come with a separate official hour recommendation, but the stakes of short sleep increase. Women who get fewer than 6 hours of sleep in a 24-hour period face higher risks of preeclampsia, gestational diabetes, longer labors, and cesarean delivery.
The challenge is that pregnancy itself makes sleep harder at almost every stage. In the first trimester, a surge in progesterone causes intense drowsiness during the day but doesn’t always translate to better nighttime sleep. The second trimester often brings some relief. By the third trimester, a growing belly, frequent urination, acid reflux, nasal congestion from hormonal swelling, and restless legs syndrome can all conspire against a full night’s rest. Restless legs syndrome alone is one of the most common causes of sleeplessness during pregnancy.
If you’re pregnant and struggling to reach 7 hours, naps count toward your total. Prioritizing sleep during pregnancy isn’t a luxury; it directly affects outcomes for both you and the baby.
Athletes and High-Demand Lifestyles
If you’re training hard physically or under sustained cognitive demand, the standard 7-hour minimum probably isn’t enough. Research on athletic recovery suggests that most athletes need 7 to 9 hours, with 80 to 90% of that coming from nighttime sleep. Adolescent athletes in heavy training may need up to 10 hours. Elite athletes training 4 to 6 hours per day may need 10 to 12 hours.
The simplest test is whether you feel alert and wakeful throughout the entire day without caffeine. If you’re dragging by mid-afternoon or relying on stimulants to function, you likely need more sleep than you’re getting, regardless of what the minimum guidelines say. The ranges listed above are floors, not targets. Your personal sweet spot may be an hour or two above the minimum for your age group.
Finding Your Personal Number
Guidelines give you a range, but your ideal amount falls somewhere specific within it. Two adults of the same age can genuinely differ by an hour or more in how much sleep they need to function well. Genetics, activity level, health status, and sleep quality all play a role.
The most reliable way to find your number is to pick a two-week stretch where you can go to bed when you’re tired and wake up without an alarm. Most people settle into a consistent pattern within a few days once they’ve paid off any accumulated sleep debt. The amount you naturally gravitate toward after that adjustment period is a good estimate of your true need.
If that experiment isn’t realistic, pay attention to two things: how long it takes you to fall asleep and how you feel by mid-afternoon. Falling asleep within 5 minutes of lying down suggests you’re significantly sleep-deprived (a well-rested person typically takes 10 to 20 minutes). And needing caffeine or a nap to get through the afternoon is a reliable sign that your overnight sleep isn’t sufficient, even if the total hours technically meet the minimum.