Sleep Calculator
Fall asleep at one of these times:
How the calculation works
Sleep moves through cycles of roughly 90 minutes. Waking at the end of a cycle often feels easier than waking from deep sleep. The calculator adds about 15 minutes to fall asleep, then counts in 90 minute steps and shows options for 4, 5 and 6 cycles.
Going to bed now? Tap the button and get wake-up times. Need to be up at 07:00? Enter it and get bedtimes.
From result to alarm
Tap any suggested time to set it on the online alarm clock. Cycle length varies from person to person, so treat the result as a guide and adjust after a few nights.
Questions
How long is a sleep cycle?
About 90 minutes on average, though it varies between people and through the night.
How many cycles do I need?
Five or six cycles, about 7.5 to 9 hours, suits most adults.
Is this a medical tool?
No. It is a simple calculation for planning sleep, not a diagnosis.