Find the best time to go to sleep or wake up based on 90-minute sleep cycles, so you wake up feeling refreshed.
Sleep cycles average about 90 minutes each. These times also add 15 minutes for the average time it takes to fall asleep.
Sleep happens in cycles of roughly 90 minutes, and waking up mid-cycle tends to feel groggier than waking at the end of one. This calculator works backward from your wake-up time to suggest bedtimes that align with full sleep cycles, so you wake up feeling more rested.
Sleep happens in cycles of roughly 90 minutes. Waking up in the middle of a cycle often leaves you feeling groggy, while waking up between cycles tends to feel more refreshing. This calculator suggests bedtimes or wake-up times aligned to full sleep cycles.
Sleep happens in cycles of roughly 90 minutes. Waking up in the middle of a cycle often leaves you feeling groggy, while waking up between cycles tends to feel more refreshing.
It suggests bedtimes or wake-up times aligned to full sleep cycles, so you wake up feeling refreshed.
Yes — enter when you plan to fall asleep, and the calculator suggests wake-up times aligned to the end of a full 90-minute sleep cycle, since waking mid-cycle is what typically causes grogginess.
Yes — enter when you need to wake up, and it works backward through 90-minute sleep cycles to suggest bedtimes that let you wake at the end of a cycle rather than in the middle of one.
Waking up in the middle of a roughly 90-minute sleep cycle often leaves you feeling groggy, compared to waking up between cycles.