Most adults need 7 or more hours of sleep a night, teenagers need 8 to 10 hours, and school-age children need 9 to 12 hours, according to the CDC. Sleep needs change across your lifespan, and while the exact figure varies a little from person to person, these age-based ranges are the best evidence-based guide for how many hours of sleep you need.
Recommended sleep by age
The CDC publishes recommended sleep amounts per 24 hours by age group (younger ages include naps):
| Age group | Recommended sleep |
|---|---|
| Newborn (0-3 months) | 14-17 hours |
| Infant (4-12 months) | 12-16 hours (incl. naps) |
| Toddler (1-2 years) | 11-14 hours (incl. naps) |
| Preschool (3-5 years) | 10-13 hours (incl. naps) |
| School age (6-12 years) | 9-12 hours |
| Teen (13-18 years) | 8-10 hours |
| Adult (18-60 years) | 7 or more hours |
| Adult (61-64 years) | 7-9 hours |
| Older adult (65+ years) | 7-8 hours |
These are ranges, not exact targets, because a small amount of natural variation is normal. Two healthy adults can feel their best on slightly different amounts within the recommended band. What the evidence is clear about is the floor: for most adults, regularly getting under 7 hours is where the risks start to climb.
Quality counts, not just hours
Time in bed is only half the story. Uninterrupted, good-quality sleep that moves through its normal cycles – light sleep, deep sleep and REM – is more restorative than a longer but fragmented night. Each cycle lasts roughly 90 minutes, and you need several complete ones to feel rested. If you spend 8 hours in bed but wake repeatedly, you may still feel unrested because those cycles keep getting interrupted before they finish. Signs of decent quality include falling asleep within a reasonable time (around 15-20 minutes), staying asleep through the night, and waking feeling refreshed rather than groggy.
How sleep changes with age. The headline totals shift downward from infancy to adulthood, but the pattern of sleep changes too. Newborns sleep in short bursts around the clock. Teenagers not only need more sleep than adults (8-10 hours) but also experience a natural shift in their body clock that makes them want to sleep and wake later – one reason early school start times leave so many tired. In older adults, the total need stays around 7-8 hours, but sleep often becomes lighter, with more night-time waking and earlier rising. That is a change in pattern, not proof that older people need far less sleep – a common misconception.
What happens when you fall short
Short-term, too little sleep hits concentration, mood, reaction time and appetite regulation. Over the long term, consistently getting under the recommended amount is associated with higher risks to heart health, weight, blood sugar control and immune function. The effects build quietly, which is why chronic short sleep is easy to underestimate.
Common myths worth dropping
- “I can bank sleep.” You cannot store extra sleep in advance to cover a coming late night.
- “Weekends fix it.” A lie-in helps a little but does not fully repay a week of loss.
- “Older people need much less.” The need stays around 7-8 hours; it is the pattern that changes.
- “I do fine on 5 hours.” True short-sleepers are rare; most people who feel fine on little sleep are simply used to being tired.
- “Naps replace night sleep.” A short nap can boost alertness, but naps do not fully substitute for a solid night, and long or late naps can make it harder to fall asleep.
A short daytime nap of around 10-20 minutes can genuinely help alertness without leaving you groggy. The trouble comes with long naps or naps late in the afternoon, which eat into your night-time sleep drive and can start a cycle of poor nights and tired days.
Simple ways to sleep better
Consistency is the most powerful lever. A few evidence-backed habits:
- Keep the same wake time every day, weekends included.
- Wind down without bright screens in the last hour before bed.
- Keep the room cool, dark and quiet.
- Limit caffeine in the afternoon and heavy meals late at night.
- Get daylight and some movement during the day.
If you regularly fall short, watch for the everyday signs: needing an alarm to wake and still feeling groggy, relying on caffeine to get going, dozing off in the afternoon, irritability, and trouble concentrating. These are your body’s way of flagging a sleep debt that a single good night will not fully clear.
Sleep works together with other daily basics. See our guides on how much water you should drink a day and how many steps a day is healthy for the rest of the picture.
When to seek help
Occasional bad nights are normal. But if trouble sleeping lasts for weeks, if you snore loudly and gasp or stop breathing during sleep, or if daytime sleepiness is affecting your life, talk to a doctor – these can point to treatable conditions like insomnia or sleep apnea. This article is general information, not medical advice.
