AbraCalc

What Time to Go to Sleep to Wake Up at 6:30 AM?

To wake at 6:30 AM after 5 sleep cycles, you should fall asleep by approximately 11:00 PM.

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How to use this tool

  1. Enter wake-up time and sleep cycles in the fields above.
  2. Results update instantly as you type — or click Calculate.
  3. Read your bedtime and the full breakdown beneath it.

Timing your sleep to complete full 90-minute cycles helps you avoid waking mid-cycle feeling groggy.

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.