Sleep Cycle Calculator

Estimate your sleep timing in 90-minute cycles based on bedtime, wake-up time, and time needed to fall asleep.

The time you plan to get into bed.
The time you plan to wake up.
Used to estimate when real sleep starts.
Age changes the practical sleep-cycle target slightly.
Poor recent sleep may increase your ideal cycle count.
Choose a quick answer or a fuller cycle view.
How we calculate

We estimate when sleep actually begins by adding your selected time to fall asleep, then divide total sleep time by 90-minute cycles to estimate how many full sleep cycles you may get.