How Many Hours of Sleep Do You Need by Age?

Recommended sleep ranges

The most widely cited reference is the National Sleep Foundation consensus, published in 2015 by a panel of experts. It aligns with the American Academy of Sleep Medicine’s recommendation that adults get at least 7 hours of sleep per night:

These are ranges, not exact targets. Some people feel their best at the lower end, while others need the upper end. A good measure is whether you wake up rested and avoid excessive sleepiness during the day.

How to check how much you’re really sleeping

Many people think they sleep 8 hours because they go to bed at 11 p.m. and get up at 7 a.m. But it may take a while to fall asleep, they may wake up during the night, or they may spend time on their phone. For a week, write down when you turn out the lights and when you get up, subtract the time you were awake, and add it all up. The Hours Calculator can help you add up periods that cross midnight (from 11:40 p.m. to 6:15 a.m. is 6 hours and 35 minutes, for example).

If your average is below the recommended range for your age, try going to bed 15 minutes earlier each week rather than changing everything at once.

Sleep hygiene: what can help

1. Keep a regular schedule for going to bed and waking up, even on weekends. Big differences can act like a “social jet lag.”
2. Get natural light in the morning and keep your environment dark at night. Light helps regulate your body clock.
3. Keep screens away from your bed: the issue is less about blue light itself and more about content that keeps your brain alert. Setting a 30-minute timer to “wind down” can help build the habit — try the Online Timer.
4. Limit caffeine to the early afternoon. Its effects can last for hours. Coffee, black tea, cola, and energy drinks all count.
5. Alcohol isn’t a sleep aid: it can make you drowsy, but it disrupts sleep during the second half of the night.
6. Keep your bedroom cool, quiet, and dark. Blackout curtains and earplugs are inexpensive options.
7. Regular exercise can improve sleep, though intense activity right before bed may keep some people awake.
8. If you’re still awake after about 20 minutes, get up, do something relaxing in low light, and return to bed when you feel sleepy.

What happens when you don’t get enough sleep

One poor night’s sleep can reduce your attention, slow your reaction time, and affect your mood the next day. When too little sleep becomes a habit, studies link it to a higher risk of accidents, weight gain, high blood pressure, and poor blood sugar control, as well as effects on memory and learning. You don’t need to memorize the list: the takeaway is that sleep is part of good health, just like eating well and staying active.

Signs you may not be getting enough sleep:

• falling asleep within minutes anywhere, such as on the bus or in a meeting;
• needing several alarms and coffee to “function”;
• sleeping much longer on weekends than on weekdays;
• frequent irritability, forgetfulness, and trouble concentrating.

If you drive, take drowsiness seriously: if your eyes start to feel heavy behind the wheel, pull over somewhere safe and rest.

Naps and teens

For most adults, short naps of 20 to 30 minutes in the early afternoon can restore alertness without disrupting sleep at night. Long naps or naps late in the day may make it harder to fall asleep at night.

Teenagers are biologically inclined to feel sleepy later. Combined with early school start times, this helps explain why so many teens get less sleep than they need. Setting household routines for screen time, studying, and bedtime usually works better than nagging.

When to seek help

Talk with a doctor if you have trouble falling or staying asleep three or more nights a week for months, someone notices you snoring loudly with pauses in your breathing, sleepiness interferes with driving or work, or you have restless legs at night. Chronic insomnia and sleep apnea can be treated.

Sources: National Sleep Foundation — recommended sleep durations; Health information library. Updated October 2026. This content is for informational purposes and does not replace advice from a doctor, dietitian, or other health professional.

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