The amount of sleep you need changes significantly over your lifetime, from around 14 to 17 hours as a newborn down to 7 to 8 hours once you’re over 65. These ranges come from guidelines set by the National Sleep Foundation and the American Academy of Sleep Medicine, and they reflect what the body actually requires at each stage of development. Here’s the full breakdown, along with what’s happening in your body that makes each age so different.
Recommended Sleep by Age
- 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
- Teenagers (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
These numbers represent total sleep per 24-hour period. For babies and toddlers, that includes daytime naps, not just overnight sleep.
How Naps Factor In for Babies and Toddlers
Young children can’t consolidate all their sleep into one nighttime stretch, so naps make up a significant portion of the total. At around 6 months, babies typically need 10 to 11 hours of nighttime sleep plus three daytime naps of one to two hours each. By 9 months to a year, most babies drop to two naps a day while still sleeping 10 to 12 hours at night.
Around 18 months, children usually transition to a single nap of one to two hours, typically around lunchtime, and this pattern holds through age 2. Most children phase out naps entirely somewhere between ages 3 and 5, which is part of why the recommended total drops from 11 to 14 hours for toddlers to 10 to 13 hours for preschoolers.
Why Children Need So Much More Sleep
Sleep isn’t just rest. It’s when the body does critical building and repair work. During deep sleep, the body ramps up production of growth hormone through a pathway called the growth hormone/IGF-1 axis. When sleep is cut short, levels of these growth-promoting signals drop measurably. When sleep is extended, they increase. This is one reason pediatric sleep needs are so much higher: children’s bodies are literally growing overnight.
Sleep also plays a direct role in brain development. Memory consolidation and the remodeling of brain connections happen actively during sleep, particularly during the dreaming phase. For children who are learning language, motor skills, and social rules at a staggering pace, these overnight processes are essential. The brain doesn’t just store the day’s learning during sleep. It reorganizes and strengthens it.
Why Teenagers Stay Up Late
If your teenager can’t fall asleep before midnight and can’t wake up before 10 a.m., that’s not laziness. It’s biology. During puberty, the body’s internal clock shifts later in a process called circadian phase delay. Two things drive this shift: the brain’s master clock changes its timing as puberty progresses, and the buildup of sleep pressure (the feeling of drowsiness that accumulates throughout the day) slows down in older adolescents. That slower buildup lets teens stay alert later into the evening, pushing their natural sleep window later.
The problem is that school start times don’t shift with them. A teenager who naturally falls asleep at 11:30 p.m. and needs 8 to 10 hours of sleep is biologically set up to wake around 7:30 to 9:30 a.m. A 6:30 a.m. alarm means chronic sleep loss during the school year.
How Sleep Changes After 65
The total sleep older adults need doesn’t drop dramatically. At 7 to 8 hours, it’s only slightly less than what younger adults need. What changes is the quality and structure of sleep. Older adults spend less time in the deepest, most restorative sleep stages. They also wake up more frequently, an average of three to four times per night, which fragments what might otherwise be adequate total sleep time.
This is why many older adults feel like they’re not sleeping enough even when they’re technically in bed for seven or more hours. The sleep they’re getting is lighter and more broken. Total time in bed often stays the same or drops only to about 6.5 to 7 hours, but the subjective experience of rest changes significantly.
Health Risks of Getting Too Little or Too Much
For adults, the sweet spot appears to be around 7 to 8 hours. A large body of research links both short sleep (under 7 hours) and long sleep (over 9 hours) to higher rates of obesity, high blood pressure, type 2 diabetes, and heart disease. The lowest risk of cardiovascular disease shows up at about 7.5 hours per night.
The risks on the long-sleep side are surprisingly steep. Compared to people sleeping 7 to 8 hours, those regularly sleeping 9 hours have a 14% higher risk of dying from any cause. At 10 hours, that rises to 30%. At 11 hours, it’s 47%. On the short end, sleeping 6 hours or fewer is associated with increased stroke risk. Consistently sleeping under 7 hours raises the probability of developing cardiovascular disease, and the evidence supporting this link is considered strong by the American Heart Association.
Long sleep isn’t necessarily causing these problems directly. In many cases, it’s a marker of underlying conditions like depression, chronic pain, or sleep disorders that fragment nighttime rest and lead to excessive time in bed. But the pattern is consistent enough to be worth paying attention to.
Napping for Adults
Short naps of 30 minutes or less can improve alertness and cognitive performance in adults. Moderate naps of 30 to 90 minutes also appear to have benefits, regardless of whether you’re a habitual napper. But naps longer than 90 minutes are a different story. In a study of older adults, extended nappers scored significantly lower on cognitive tests than non-nappers, even after accounting for factors like age, education, and chronic conditions like diabetes and high blood pressure. If you nap, keeping it under 30 minutes is the safest bet for avoiding grogginess and nighttime sleep disruption.
Can Some People Get By on Less?
A very small number of people are genuine short sleepers, functioning well on 4 to 6 hours without any negative effects. Researchers have identified specific gene variants (in genes called DEC2 and ADRB1) linked to this trait. So far, only about 50 families worldwide have been confirmed to carry these mutations, making true short sleeper syndrome extremely rare. The vast majority of people who believe they function fine on 5 or 6 hours are simply accustomed to being sleep-deprived. The body adapts to chronic sleep loss in ways that mask how impaired you actually are, particularly in reaction time, decision-making, and emotional regulation.