Sleep Calculator
Find the best time to wake up based on 90-minute sleep cycles.
Bedtime
When do you plan to go to sleep?
:
It takes ~15 minutes to fall asleep. You should be sleeping by 02:10 AM.
Wake-up times
Waking at the end of a complete cycle helps you feel refreshed.
03:40 AMLight sleep
1 cycle · 1h 30m of sleep05:10 AMLight sleep
2 cycles · 3h of sleep06:40 AMLight sleep
3 cycles · 4h 30m of sleep08:10 AMRecommended
4 cycles · 6h of sleep09:40 AMRecommended
5 cycles · 7h 30m of sleep11:10 AMFull rest
6 cycles · 9h of sleepA sleep cycle lasts ~90 minutes. Most adults need 4–6 cycles (6–9 hours) per night.