What Time to Go to Sleep to Wake Up at 8 AM?
To wake at 8:00 AM after 5 sleep cycles, you should fall asleep by around 12:15 AM.
How to use this tool
- Enter wake-up time and sleep cycles in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your bedtime and the full breakdown beneath it.
Use this sleep cycle calculator to find the ideal bedtime for waking up at 8:00 AM.
Frequently asked questions
- How long is a sleep cycle?
- Each sleep cycle lasts approximately 90 minutes, moving through light sleep, deep sleep, and REM. Most adults complete 4–6 cycles per night.
- How many hours of sleep do I need?
- Adults generally need 7–9 hours (roughly 5–6 cycles). Teenagers need 8–10 hours; children need more.