Calculate your sleep cycles and wake up at the perfect time in your light sleep phase
Wake up during light sleep phases to feel refreshed and energized
Uses 90-minute sleep cycle theory for accurate calculations
Plan your bedtime or wake-up time for optimal rest
Sleep occurs in cycles that last about 90 minutes each. Each cycle consists of four stages: light sleep, deep sleep, and REM (rapid eye movement) sleep. Waking up at the end of a complete cycle, during light sleep, helps you feel more rested and alert.
| Age Group | Recommended Hours | Sleep Cycles |
|---|---|---|
| Newborns (0-3 months) | 14-17 hours | 9-11 cycles |
| Adults (18-64 years) | 7-9 hours | 5-6 cycles |
| Older Adults (65+ years) | 7-8 hours | 5 cycles |
Most adults need 5-6 complete sleep cycles (7.5-9 hours) for optimal rest. However, individual needs may vary based on age, lifestyle, and sleep quality.
While 4 cycles (6 hours) might be sufficient for some people occasionally, consistently getting only 4 cycles can lead to sleep deprivation over time. It's better to aim for 5-6 cycles regularly.
Waking during deep sleep can cause sleep inertia - that groggy, disoriented feeling. This is why our calculator helps you wake up between cycles during lighter sleep stages.
⚠️ Disclaimer: This sleep calculator provides recommendations based on average sleep cycle patterns. Individual sleep needs may vary. Consult a healthcare professional for persistent sleep issues or medical concerns.
