Sleep cycle calculator
Pick when you want to wake up, or when you're going to sleep, and see times that land at the end of a sleep cycle, when waking up tends to feel easier.
Most people take about 10 to 20 minutes. 15 is an average.
90 minutes is an average. Real cycles run about 90 to 110 minutes and change through the night and from person to person, so treat the times as a guide.
Runs on your phone. Nothing is uploaded or saved.
School-night helper
When does your child need to be in bed to get enough sleep before school?
How much sleep is recommended?
Through the night you move through lighter sleep, deep sleep and dream (REM) sleep in cycles of roughly 90 to 110 minutes. Waking from deep sleep can leave you groggy, so many people find it easier to wake near the end of a cycle.
Timing can't make up for too little sleep. Pick the option that gives you the recommended hours for your age, and keep the same wake-up time on most days.
Dropping off in under 5 minutes can be a sign you're short of sleep. Regularly lying awake for 30 minutes or more, at least three nights a week for over three months, is worth raising with a doctor.
This is a general guide. If you snore loudly, stop breathing in your sleep, or feel very sleepy in the day even after enough hours, see a doctor.
Sources: Paruthi S et al., "Recommended amount of sleep for pediatric populations: a consensus statement of the American Academy of Sleep Medicine", Journal of Clinical Sleep Medicine, 2016;12(6):785–786 (4–12 months 12–16 h, 1–2 years 11–14 h, 3–5 years 10–13 h including naps; 6–12 years 9–12 h; 13–18 years 8–10 h); Watson NF et al., "Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society", Journal of Clinical Sleep Medicine, 2015;11(6):591–592 (adults: 7 hours or more); Hirshkowitz M et al., "National Sleep Foundation's sleep time duration recommendations: methodology and results summary", Sleep Health, 2015;1(1):40–43 (adults 18–64: 7–9 h; 65 and over: 7–8 h). Cycle length: University Hospitals (Cleveland, Ohio) health library, "Stages of sleep" (cycles of about 90 to 110 minutes). Time to fall asleep: Cleveland Clinic, "How long should it take to fall asleep?" (about 10 to 20 minutes on average; under 5 minutes may mean sleep deprivation; 30 minutes or more, three nights a week for three months, may point to insomnia). The calculator uses fixed averages, so real cycles will differ. Not medical advice.