How it works
The calculator uses common 90-minute sleep cycle estimates. Enter a target wake-up time to get suggested bedtimes, or enter a bedtime to get suggested wake-up times.
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Sleep Calculator
Estimate bedtime and wake-up time using sleep cycles.
Fall-asleep buffer
Most people need time to fall asleep, so the tool includes a configurable buffer. The default is 15 minutes.
Health note
Sleep cycles are estimates. Persistent insomnia, fatigue or sleep issues should be discussed with a qualified professional.
FAQ
Why 90 minutes?
It is a common estimate for a full sleep cycle, but individual sleep patterns vary.
Can it plan naps?
Yes, though short naps are often closer to 20-30 minutes or one full cycle.