How do I calculate my best wake-up time?

Start with the time you plan to go to sleep and add the amount of rest you need, usually seven to nine hours for most adults. Include the time it normally takes you to fall asleep. For example, if you get into bed at 10:30 p.m., take 20 minutes to fall asleep and need eight hours, a reasonable wake-up time would be around 6:50 a.m. Sleep calculators may suggest times based on four, five or six estimated cycles, but cycle lengths vary. Choose a wake-up time that supports your responsibilities and can remain consistent most days. If you regularly wake feeling exhausted, you may need an earlier bedtime, better sleep habits or an assessment for disrupted sleep.