Sleep Calculator

Wake up refreshed by completing full sleep cycles 😴

I want to go to sleep at:

Best times to wake up:

💡 Times highlighted in green give you 7-9 hours of recommended sleep.

How Sleep Cycles Work

Sleep happens in 90-minute cycles. Each cycle includes light sleep, deep sleep, and REM sleep. Waking up between cycles (rather than in the middle of one) helps you feel more refreshed.

The average person needs 5-6 complete cycles (7.5-9 hours) per night. Our calculator adds 15 minutes to fall asleep and calculates optimal wake times based on complete cycles.

🔬Science-Based
🎁100% Free
📱Mobile Friendly

FAQ

How long is a sleep cycle?

One complete sleep cycle is approximately 90 minutes. Most adults need 5-6 cycles per night.

Why do I feel tired after 8 hours?

You may be waking up mid-cycle. Try adjusting your wake time by 30 minutes earlier or later.

How long does it take to fall asleep?

We factor in 15 minutes to fall asleep. If you take longer, adjust accordingly.

How much sleep do I need?

Adults typically need 7-9 hours (5-6 cycles). Teens need 8-10, and children need even more.