Sleep Cycle Calculator

Calculate your optimal bedtime or wake-up time based on 90-minute sleep cycles. Wake up feeling refreshed by timing your sleep with your natural REM cycles.

Tips for Better Sleep

1Keep a consistent sleep schedule, even on weekends.
2Avoid screens for at least 30 minutes before bed.
3Keep your bedroom cool, dark, and quiet.
4Avoid caffeine at least 6 hours before bedtime.
5Try a relaxing bedtime routine like journaling or reading.
6Exercise regularly, but not within 3 hours of bedtime.

Understanding Sleep Cycles

Sleep occurs in cycles of approximately 90 minutes. Each cycle includes stages of light sleep, deep sleep, and REM (rapid eye movement) sleep. Waking up at the end of a complete cycle, rather than in the middle of one, helps you feel more rested and alert.

How Many Sleep Cycles Do You Need?

Most adults need 5 to 6 complete sleep cycles per night, which equals 7.5 to 9 hours of sleep. However, individual needs vary. Some people function well on 4 cycles (6 hours), while others need 7 cycles (10.5 hours). The key is to find what works best for your body and to wake up at the end of a cycle.

Why Timing Matters More Than Duration

Sleeping for 7.5 hours (5 cycles) can leave you feeling more refreshed than sleeping 8 hours, because 8 hours means you wake up during the middle of a sleep cycle. This calculator helps you align your schedule with your natural sleep rhythms for optimal rest.