Sleep schedule calculator

How it works

Bedtime = wake-up time − sleep duration − time to fall asleep. Wake-up time = bedtime + sleep duration + time to fall asleep. Times wrap across midnight and are shown relative to the day of the time you enter.

This is a clock-based planner for adults, not a prediction of your sleep stages or a guarantee of feeling rested. Most adults need 7–9 hours, but individual needs vary. Sleep cycles are not a fixed 90 minutes. Clock changes and time-zone travel are not included.

Sources: NIH: Healthy Sleep · NHLBI: Sleep stages

Example

To wake at 07:00 after eight hours asleep, allowing 15 minutes to fall asleep, plan bedtime for 22:45 the previous day.