Sleep Calculator
Enter when you need to wake up to get bedtimes that line up with full sleep cycles, or enter when you're going to bed to see the best wake-up times.
Frequently asked questions
What time should I go to bed to wake up at 7 a.m.?
Around 9:45 p.m. for six cycles (9 hours) or 11:15 p.m. for five cycles (7.5 hours), allowing 15 minutes to fall asleep.
How much sleep do adults need?
Sleep experts recommend 7 to 9 hours a night for adults; the 90-minute cycle is an average, and yours may be a little shorter or longer.