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Sleep Calculator: What Time Should I Go to Bed?
Choose the time you need to wake up and this calculator shows bedtimes that let you wake near the end of a sleep cycle. It counts back in cycles of about 90 minutes and adds roughly 15 minutes for falling asleep.
When should you go to bed?
Sleep happens in cycles of about 90 minutes. Waking up at the end of a cycle, instead of in the middle, can help you feel fresher. Choose your wake-up time to see the best bedtimes.
Includes about 15 minutes to fall asleep. Most adults need 7–9 hours of sleep a night.
How the sleep calculator works
During the night you move through repeating sleep cycles that last about 90 minutes on average, though the exact length varies from person to person and from night to night. Waking at the end of a cycle, rather than in the middle of deep sleep, may help you feel less groggy.
The calculator starts from your wake-up time, subtracts about 15 minutes to fall asleep, then counts back in 90-minute cycles. Five or six cycles works out to roughly 7.5 to 9 hours in bed.
How much sleep do adults need?
The CDC recommends that adults get 7 or more hours of sleep per night. Use the later bedtimes only on nights when you cannot get to bed earlier.
Tips for using your bedtime
- Keep the same wake-up time on most days, including weekends.
- Start winding down 30 to 60 minutes before your chosen bedtime.
- Get daylight in the morning and limit caffeine later in the day.
- Track your days with our daily habit tracker.
If you often feel tired after a full night in bed, snore loudly or struggle to fall asleep, talk with a healthcare professional.
This tool gives general estimates for education only and is not medical advice. See our Medical Disclaimer.