Sleep cycle planner

With a wake-up time, the calculator subtracts the assumed sleep duration and time to fall asleep. With a bedtime, it adds both. Sleep duration is cycle count × cycle length; the total also includes falling asleep. The highlighted row is your selected count.

Days are relative to the day of the entered time. This clock model uses exactly 24 hours per day and does not include dates, time zones, daylight-saving changes or alarms. Whole-minute calculation ranges are 30–180 minutes per cycle and 0–180 minutes to fall asleep, with 1–8 cycles. These are calculation limits, not health recommendations.

Real cycles and sleep phases vary. This calculation cannot identify a sleep phase or guarantee restorative sleep. Background: NIH/NHLBI: Sleep Phases and Stages (source checked 14 September 2026).