Your sleep
Enter your alarm time — we’ll work backwards to find the best bedtime.
Your results
Enter your time and press
Calculate sleep times
Calculate sleep times
Recommended bedtimes
Sleep cycles (recommended option)
Sleep duration
--
Full cycles
--
Recommended range
7–9 hrs
Fall-asleep buffer
15 min
Why 90 minutes? A full sleep cycle lasts roughly 90 minutes and includes light sleep, deep sleep and REM. Waking mid-cycle — especially during deep sleep — causes sleep inertia: that heavy, disoriented feeling. Timing your alarm to land at the end of a cycle helps you wake naturally from lighter sleep.
Sleep cycle durations vary between individuals and change across the night. This calculator provides general guidance based on a 90-minute average. If you experience persistent sleep difficulties, daytime drowsiness, or suspect a sleep disorder, please consult a GP or sleep specialist.