Sleep Cycle Calculator
What time do you want to wake up?
:
If you want to go to bed now...
Sleep Cycle Calculator
What time do you want to wake up?
If you want to go to bed now...
Frequently Asked Questions
A sleep cycle is approximately 90 minutes long and consists of different sleep stages including light sleep, deep sleep, and REM sleep. Waking up at the end of a complete cycle helps you feel more refreshed.
Most adults need 5-6 complete sleep cycles per night, which equals 7.5-9 hours of sleep. However, 4 cycles (6 hours) can work occasionally, though it's not recommended regularly.
The average person takes about 15 minutes to fall asleep. The calculator accounts for this time so your sleep cycles begin from when you actually fall asleep, not when you get into bed.
If you wake up in the middle of a sleep cycle, you may feel groggy regardless of total sleep time. This calculator helps you wake up between cycles when you're in lighter sleep.
The best bedtime depends on when you need to wake up. Count back in 90-minute cycles from your wake time, adding 15 minutes to fall asleep. For a 7 AM wake-up, ideal bedtimes are 9:45 PM, 11:15 PM, or 12:45 AM.