Sleep Cycle Calculator
Optimize your sleep schedule based on natural sleep cycles. Find the perfect bedtime and wake-up times to feel refreshed and energized every morning.
What would you like to calculate?
Your Sleep Schedule
Optimal sleep and wake times
Find Your Optimal Bedtime
Enter your wake-up time to find the best bedtime for complete sleep cycles.
When do you need to wake up?
When do you want to go to bed?
Sleep Preferences
Sleep Habits
Optimal Sleep Times
Sleep Science
Sleep Cycles
A complete sleep cycle lasts about 90 minutes and includes 4 stages: Light sleep, Deep sleep, and REM sleep.
Optimal Timing
Waking up at the end of a sleep cycle (after 1.5, 3, 4.5, 6, 7.5, or 9 hours) helps you feel more refreshed and alert.
Sleep Stages
- • Light Sleep: 45-55% of total sleep
- • Deep Sleep: 15-20% of total sleep
- • REM Sleep: 20-25% of total sleep
- • Awake: 5% or less is normal
Chronotypes
Sleep Duration by Age
Sleep Facts
- • We spend about 1/3 of our lives sleeping
- • Dreams occur mainly during REM sleep
- • Body temperature drops during sleep
- • Growth hormone is released during deep sleep
- • Memory consolidation happens during sleep
- • Immune system strengthens during rest
Sleep Myths
- • ❌ You can "catch up" on lost sleep
- • ❌ Older adults need less sleep
- • ❌ Snoring is always harmless
- • ❌ Alcohol helps you sleep better
- • ❌ You can function well on 4-5 hours
- • ❌ Watching TV helps you fall asleep
Sleep Cycle Calculator Answers
What does the sleep cycle calculator do?
It helps you determine the best times to go to bed or wake up based on natural 90-minute sleep cycles. The goal is to wake up at the end of a cycle when you're most likely to feel refreshed.
Why are sleep cycles important?
Sleep cycles consist of light, deep, and REM sleep stages. Waking during deep sleep can make you feel groggy, while waking between cycles—usually every 90 minutes—can help you feel more alert.
How many cycles do I need each night?
Most adults need 4–6 complete sleep cycles per night, which equals 6 to 9 hours of sleep. This varies by age, lifestyle, and individual sleep needs.
Does this replace good sleep habits?
No. While timing your sleep cycles can help improve restfulness, consistent bedtime routines, avoiding screens, and managing stress are essential for quality sleep.