Sleep Calculator
Find the best time to go to sleep or wake up based on 90-minute sleep cycles for optimal rest and energy.
You should go to bed at one of these times:
9:46 PM
6 cycles · 9 hours of sleep
Excellent
11:16 PM
5 cycles · 7.5 hours of sleep
Good
12:46 AM
4 cycles · 6 hours of sleep
Fair
2:16 AM
3 cycles · 4.5 hours of sleep
Poor
How Sleep Cycles Work
Sleep occurs in cycles of approximately 90 minutes. Each cycle includes light sleep, deep sleep, and REM (rapid eye movement) sleep. Waking up at the end of a complete cycle — rather than in the middle — helps you feel more refreshed and alert.
Newborns (0–3 months)14–17 hours
Infants (4–11 months)12–15 hours
Toddlers (1–2 years)11–14 hours
School-age (6–13)9–11 hours
Teenagers (14–17)8–10 hours
Adults (18–64)7–9 hours
Older adults (65+)7–8 hours