Find the best times to sleep or wake up based on 90-minute sleep cycles. Waking between cycles helps you feel more refreshed.
Assumes ~15 minutes to fall asleep. Sleep cycles are approximately 90 minutes each.
Choose whether you want to calculate bedtime (based on wake-up time) or wake-up time (based on bedtime).
Enter your target time.
Click Calculate to see optimal times aligned with sleep cycles.
A full sleep cycle lasts approximately 90 minutes and includes light sleep, deep sleep, and REM stages. Waking at the end of a complete cycle (rather than mid-cycle) helps you feel more alert and rested.
Disclaimer: This calculator is for informational purposes only and is not medical advice. Sleep needs vary by individual. Consult a healthcare professional if you have sleep concerns.
Most adults need 7-9 hours of sleep per night (5-6 complete sleep cycles). Keeping a consistent sleep schedule -- even on weekends -- helps regulate your body clock.