How much sleep do I need by age?
Sleep needs change across life. Most adults need 7–9 hours a night — about 5 to 6 full sleep cycles — while babies, children and teens need considerably more. Use the chart below as a starting point, then fine-tune the timing with the sleep calculator.
Recommended sleep by age
| Age group | Recommended sleep |
|---|---|
| Newborns (0–3 mo) | 14–17 hours |
| Infants (4–11 mo) | 12–15 hours |
| Toddlers (1–2 yr) | 11–14 hours |
| Preschool (3–5 yr) | 10–13 hours |
| School age (6–13 yr) | 9–11 hours |
| Teens (14–17 yr) | 8–10 hours |
| Adults (18–64 yr) | 7–9 hours |
| Older adults (65+) | 7–8 hours |
Ranges follow widely cited expert guidance (e.g. the National Sleep Foundation). They are general guidance only, not medical advice — individual needs vary.
Sleep duration in cycles
Because a cycle averages 90 minutes, adult targets line up neatly with whole cycles: 7.5 hours is five cycles and 9 hours is six. Aiming for a whole number of cycles helps your alarm fall in light sleep. The calculator does this math for you.
| Total sleep | Cycles |
|---|---|
| 6 hours | 4 cycles |
| 7.5 hours | 5 cycles |
| 9 hours | 6 cycles |
Signs you're not getting enough
- Needing an alarm to wake and feeling groggy well past it.
- Daytime sleepiness, trouble concentrating, or irritability.
- Relying on caffeine to get through the afternoon.
- "Catching up" with much longer sleep on weekends.
If you consistently fall short, shifting your bedtime earlier by one full cycle (90 minutes) is an easier change than trying to add a random 30 minutes.
Quality matters too
Hours are only part of the picture. Fragmented sleep, irregular schedules, alcohol, late caffeine and screens all reduce how restorative your sleep is even if the total looks fine. Keep a consistent wake time, get morning light, and keep the bedroom cool and dark.
This article is general educational information, not medical advice. For persistent sleep problems or suspected sleep disorders, consult a qualified healthcare professional.
Related
Sleep calculator · What is a sleep cycle? · Nap calculator · If I go to sleep now