Sleep Cycle Calculator
Find the best time to go to bed based on your desired wake-up time and 90-minute sleep cycles.
6 cycles (9h)
9:45 PM
5 cycles (7.5h)
11:15 PM
4 cycles (6h)
12:45 AM
How Sleep Cycles Work
Each sleep cycle lasts about 90 minutes. Waking up at the end of a cycle leaves you feeling refreshed, while waking mid-cycle causes grogginess. Aim for 5 full cycles per night.
Frequently Asked Questions
Sleep Cycle Calculator Guide
Our sleep cycle calculator uses the 90-minute sleep cycle formula to recommend bedtimes that align with your body's natural sleep rhythms. By timing your bedtime so you wake at the end of a cycle, you can minimize morning grogginess.
For best results, maintain a consistent sleep schedule and aim for at least 5 full cycles (7.5 hours) each night.