Free sleep timing tool
Find a realistic sleep time
Use this sleep cycle calculator to estimate bedtime or wake-up times based on common 90-minute sleep cycles.
This tool gives general timing estimates only. It does not diagnose sleep problems or replace medical advice.
How this sleep cycle calculator works
This sleep cycle calculator uses a common estimate of about 90 minutes per sleep cycle.
It also lets you add time to fall asleep, because going to bed and actually sleeping are not always the same thing.
The results are estimates. Real sleep can be affected by stress, light, caffeine, schedule changes, health, and many other factors.
How to use the results
Pick the option that fits your real evening, not only the option that looks perfect.
If the ideal bedtime is unrealistic, choose the next possible option and make the evening easier to start.
You can use the Daily Wellness Planner to write your sleep target for tomorrow.
If you want the plain explanation behind the timing, read how sleep cycles work.
If your bedtime has drifted, read how to fix a sleep schedule with small repeatable changes.
Simple example
If you want to wake up at 7:00 AM and usually need 15 minutes to fall asleep, the calculator gives a few bedtime options.
- 9:45 PM for about 6 sleep cycles.
- 11:15 PM for about 5 sleep cycles.
- 12:45 AM for about 4 sleep cycles.
If the earliest option is unrealistic, choose the latest option that still gives you enough rest.
The goal is not to force a perfect schedule. The goal is to make sleep timing easier to think about.
Privacy note
This calculator runs in your browser. WellnessTract does not receive the time you enter.
FAQ
Is 90 minutes always one sleep cycle?
No. Ninety minutes is a common estimate, but sleep cycles vary from person to person and night to night.
Should I always wake up at the end of a cycle?
It can be a useful idea, but it is not a rule. Enough sleep, a steady routine, and a realistic schedule still matter.
Is this medical advice?
No. This tool is for general education and planning. If sleep problems are ongoing or serious, speak with a qualified health professional.
Next step: use the Daily Wellness Planner to set one realistic sleep target for tomorrow.