Sleep Cycle Calculator
Bedtimes that match 90-minute sleep cycles for your wake-up time.
How it works
A sleep cycle lasts about 90 minutes, and most people need 5 to 6 of them. The times include roughly 15 minutes to fall asleep. Waking at the end of a cycle often feels easier than waking in the middle of one.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.