Sleep Calculator
I want to wake up at...
Find out when you should go to bed.
If I go to bed now...
Find out when you should wake up.
How Sleep Cycles Work
A good night's sleep consists of 5-6 complete sleep cycles. Each cycle lasts roughly 90 minutes. Waking up in the middle of a sleep cycle leaves you feeling tired and groggy, but waking up between cycles wakes you up feeling refreshed and alert.
This calculator counts backwards or forwards in 90-minute increments, and factors in the average 15 minutes it takes to fall asleep.