Sleep Calculator
Calculate optimal sleep and wake times based on 90-minute sleep cycles. Wake up feeling refreshed.
100% Private
Instant
Any Device
Free ForeverWhen to Sleep
Enter when you need to wake up
21:456 cycles • 9h
Recommended
23:155 cycles • 7.5h
Recommended
00:454 cycles • 6h
02:153 cycles • 4.5h
When to Wake Up
Enter when you're going to sleep
08:156 cycles • 9h
Recommended
06:455 cycles • 7.5h
Recommended
05:154 cycles • 6h
03:453 cycles • 4.5h
About Sleep Cycles:
A complete sleep cycle lasts about 90 minutes. Waking up at the end of a cycle helps you feel more refreshed. The calculator adds 15 minutes to fall asleep. Adults typically need 5-6 cycles (7.5-9 hours) per night.
