How Much Sleep Do You Need? Hours by Age and the Best Time to Go to Bed
Published 2026-10-29
Most adults know they should “get eight hours”, yet about a third of US adults regularly sleep less than they need. The right amount depends mostly on your age, and the right bedtime depends on when you have to get up. Here is what health experts recommend, and how to turn it into a schedule with the sleep calculator.
Recommended sleep by age
These are the CDC’s recommendations for total sleep in a 24-hour period:
| Age | Recommended sleep |
|---|---|
| Newborn (0–3 months) | 14–17 hours |
| Infant (4–12 months) | 12–16 hours, including naps |
| Toddler (1–2 years) | 11–14 hours, including naps |
| Preschool (3–5 years) | 10–13 hours, including naps |
| School age (6–12 years) | 9–12 hours |
| Teen (13–17 years) | 8–10 hours |
| Adult (18–60 years) | 7 or more hours |
| Adult (61–64 years) | 7–9 hours |
| Adult (65 and older) | 7–8 hours |
These are ranges, not exact targets. Some people feel fine at the low end and others need the top. A good test is whether you wake up without dragging yourself out of bed and stay alert through the afternoon without leaning on caffeine.
What a sleep cycle is
Sleep isn’t one long, even stretch. Through the night you repeat cycles that move from light sleep into deep sleep and then into REM sleep, when most dreaming happens. A cycle lasts about 90 minutes on average, though it can be anywhere from roughly 80 to 120 minutes. Early in the night the cycles contain more deep sleep; toward morning they contain more REM.
When your alarm goes off during deep sleep, you are more likely to feel groggy for a while, a state called sleep inertia. Waking near the end of a cycle, when sleep is lighter, tends to feel easier. That is the idea behind planning sleep in 90-minute blocks.
How to pick your bedtime
- Start from your wake-up time, since that is usually fixed by work or school.
- Count back five or six cycles (7½ or 9 hours). Four cycles, 6 hours, is less than adults are advised to get.
- Add the time it takes you to fall asleep, usually 10 to 20 minutes.
For a 6:30 a.m. alarm, that gives a bedtime of about 10:45 p.m. for 7½ hours or 9:15 p.m. for 9 hours. The sleep calculator works this out for any time, and can also tell you when to set the alarm if you are heading to bed right now.
Habits that help you sleep better
- Keep a regular schedule. Going to bed and getting up at the same times every day, weekends included, steadies your body clock more than anything else.
- Get morning light. Daylight soon after waking helps you feel sleepy at the right time in the evening.
- Make the bedroom dark, quiet and cool.
- Cut back on screens before bed. Bright light and scrolling keep the brain alert.
- Watch caffeine and alcohol. Caffeine can stay in your system for many hours, and alcohol disturbs sleep later in the night.
- Be active during the day, but finish hard workouts a few hours before bed.
When to talk to a doctor
If you often feel tired even after enough time in bed, snore loudly, stop breathing for moments during sleep, or have trouble falling or staying asleep for weeks at a time, speak to a doctor. Sleep apnea and insomnia are common, and both can be treated.
Frequently asked questions
Is 6 hours of sleep enough?
For most adults, no. The CDC recommends at least 7 hours for adults. Regularly sleeping 6 hours or less is linked to poorer concentration and health over time.
Can I catch up on sleep at the weekend?
A longer sleep can help you recover from a short night, but large swings between weekday and weekend schedules make Monday mornings harder. Small, regular adjustments work better.
Do naps count?
For babies and young children, yes: the recommended totals include naps. For adults, a short nap of 20 to 30 minutes can boost alertness, but it doesn’t replace a full night’s sleep.
When the clocks change, your schedule shifts too. See our guide to when daylight saving time ends for tips on adjusting.
This guide is general information, not medical advice.