🌙 Sleep Cycle Calculator

Calculate optimal sleep times based on 90-minute cycles

⏰ Choose Time

📊 Sleep Stages

  • Stage 1-2: Light sleep (20 min)
  • Stage 3: Deep sleep (40 min)
  • REM Sleep: (30 min)

Frequently Asked Questions

Adults need 7-9 hours of sleep daily for good health and optimal mental and physical performance.

A sleep cycle lasts about 90 minutes and includes 4 stages: light drowsiness, light sleep, deep sleep, and REM sleep.

You may be waking in the middle of a deep sleep cycle. Try sleeping 7.5 hours (5 complete cycles) instead of 8.

Best sleep time depends on your wake time. If waking at 6 AM, best to sleep at 10:30 PM.

Yes, 20-30 minute naps improve alertness and performance. Avoid napping after 3 PM as it may affect nighttime sleep.