How Many Hours of Sleep Do You Need?
Sleep needs vary by age and individual biology. These are evidence-based guidelines from sleep research:
By age group:
- Newborns (0–3 months): 14–17 hours
- Infants (4–11 months): 12–15 hours
- Toddlers (1–2 years): 11–14 hours
- Preschool (3–5 years): 10–13 hours
- School age (6–13): 9–11 hours
- Teens (14–17): 8–10 hours
- Young adults (18–25): 7–9 hours
- Adults (26–64): 7–9 hours
- Seniors (65+): 7–8 hours
Signs you need more sleep:
- You need an alarm to wake up
- You fall asleep within 5 minutes
- You feel tired by mid-afternoon
- You sleep significantly more on weekends
- You need caffeine to function
Signs you are getting enough:
- Wake naturally before alarm
- Feel alert within 30 minutes
- Consistent energy through the day
- Fall asleep within 15–20 minutes
Quality over quantity: 5 complete 90-minute cycles (7.5 hours) of uninterrupted sleep is better than 9 hours of frequently disturbed sleep.
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Sleep Calculator
Find the perfect bedtime or wake-up time based on 90-minute sleep cycles. Wake up refreshed, not groggy.
What time do you want to wake up?
Why 90-minute cycles?
During sleep your brain moves through cycles of light sleep, deep sleep, and REM sleep. Each cycle takes about 90 minutes. Waking at the end of a cycle — not in the middle — is why you feel refreshed instead of groggy.
How much sleep do you need?
- Teens (14–17): 8–10 hours
- Adults (18–64): 7–9 hours
- Seniors (65+): 7–8 hours
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