Sleep Calculator
Find the best time to sleep or wake up based on sleep cycles.
Results
Bedtime
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Add 15 minutes to fall asleep for optimal results.
About Sleep Cycle Calculation
Sleep cycles typically last about 90 minutes, and we pass through several stages each night. By timing your sleep or wake time to align with these natural cycles, you can wake up feeling more refreshed.
This calculator works backwards from your desired wake time (or forwards from your sleep time) to suggest optimal times, accounting for the average 15 minutes it takes to fall asleep.
Frequently Asked Questions
What are sleep cycles?
Sleep occurs in cycles of approximately 90 minutes, moving through light sleep, deep sleep, and REM sleep. Waking up at the end of a cycle, rather than in the middle, helps you feel more refreshed.
How many sleep cycles do I need?
Most adults need 4-6 sleep cycles per night (6-9 hours). The exact number varies by individual, but 5-6 cycles is a common target for most people.
Why does timing matter?
Waking up in the middle of a sleep cycle can leave you feeling groggy and tired. By timing your sleep to align with natural cycle endings, you wake up feeling more refreshed.