Many people feel better waking near the end of a sleep cycle (often described as roughly 90 minutes) rather than from deep sleep mid-cycle. A sleep calculator counts cycles backwards from your alarm.
How to use it
- Choose your wake-up time.
- Allow ~10–20 minutes to fall asleep.
- Pick a bedtime that completes 4–6 cycles if your schedule allows.
Consistency beats perfection. If you have insomnia, loud snoring, or daytime sleepiness that affects safety, talk to a qualified clinician—this tool is for planning, not diagnosis.
Try options in the Sleep Calculator and protect the bedtime you choose like any other appointment.