Sleep needs by age: a bedtime chart
How much sleep a person needs changes a lot from infancy to old age. These are the widely used recommendations, followed by how to turn them into an actual bedtime.
Recommended sleep by age
The ranges below come from the National Sleep Foundation's expert consensus, which reviewed hundreds of studies to set age-by-age targets. They are recommendations for a typical person, not strict limits; an hour either side can still be healthy for some people.
| Age group | Recommended sleep |
|---|---|
| Newborn (0 to 3 months) | 14 to 17 hours |
| Infant (4 to 11 months) | 12 to 15 hours |
| Toddler (1 to 2 years) | 11 to 14 hours |
| Preschooler (3 to 5 years) | 10 to 13 hours |
| School-age (6 to 13 years) | 9 to 11 hours |
| Teenager (14 to 17 years) | 8 to 10 hours |
| Adult (18 to 64 years) | 7 to 9 hours |
| Older adult (65+ years) | 7 to 8 hours |
Turning hours into a bedtime
For school-age children and up, you can use the same cycle math the calculator uses: count back from the wake time in 90-minute cycles, add about 15 minutes to fall asleep, and choose the option that lands inside the recommended range. For example, a 9-year-old who needs to wake at 7:00 AM and should get 9 to 11 hours does well going to bed around 8:15 PM (about ten and three-quarter hours in bed, allowing for the buffer), comfortably inside the range.
The calculator's bedtime-by-age mode does this for you: pick the age band and the wake time, and it highlights the cycle-aligned bedtimes that fall inside that age's recommended window.
Why young children are different
For babies, toddlers, and preschoolers, the neat 90-minute-cycle model does not apply. Their sleep cycles are shorter, closer to 50 to 60 minutes, and their sleep is spread across naps and night rather than one consolidated block. For these ages, focus on the total daily hours and a consistent wind-down routine rather than a single cycle-aligned bedtime. The calculator reflects this: choose a very young age band and it shows the recommended total instead of bedtimes.
Teenagers and the shifted clock
Teens genuinely need 8 to 10 hours, and their body clock naturally drifts later during puberty, which is why early school start times hit them so hard. If a teen has to be up at 6:30 AM, the math says a bedtime closer to 9:00 to 10:30 PM, which is often earlier than their body wants. Consistent wake times and morning light help pull the clock back.
A note for parents
Use these ranges as a guide, not a verdict on your child. Mood, focus, and how easily they wake are better day-to-day signals than the clock. If a child is persistently exhausted despite enough time in bed, that is worth a conversation with a pediatrician.
Source: Sleep Foundation, How Much Sleep Do We Really Need (National Sleep Foundation age recommendations).