Sleep Calculator
Calculate optimal bedtime or wake time based on 90-minute sleep cycles for better rest
Sleep Timing
Enter the time you need to wake up, and we will suggest the best times to fall asleep.
Quick Examples
Set Your Sleep Time
Choose whether you want to wake up or go to sleep at a specific time, and we will calculate the optimal sleep schedule.
Recommended Sleep Times
How Sleep Cycles Work
What Are Sleep Cycles?
During sleep, your brain cycles through stages: light sleep, deep sleep, and REM sleep. One complete cycle lasts about 90 minutes. Waking up between cycles (rather than in the middle of deep sleep) helps you feel more refreshed.
Why 90 Minutes?
Research shows that the average adult sleep cycle lasts approximately 90 minutes. By timing your sleep in 90-minute increments (3-6 cycles), you align your wake time with lighter sleep stages for a more natural awakening.
Sleep Hygiene Tips
Keep a consistent sleep schedule, limit screen time before bed, keep your bedroom cool and dark, avoid caffeine after 2 PM, and aim for 7-9 hours of sleep per night for optimal health.
Sleep Calculator FAQ
How does the sleep calculator work?
It uses the science of 90-minute sleep cycles to recommend optimal bedtimes or wake times. By aligning your wake time with the end of a sleep cycle, you wake up feeling more refreshed.
How many sleep cycles do I need?
Most adults need 4-5 sleep cycles (6-7.5 hours) per night. The optimal recommendation is 5 cycles (about 7.5 hours), which balances rest and productivity for most people.
Why do I still feel tired after 8 hours of sleep?
Waking up in the middle of a deep sleep cycle can cause grogginess, even after a long sleep. Try adjusting your bedtime to align with a full cycle for a more refreshed awakening.
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