Sleep Cycle Calculator & Nap Timer
Ever woken up after 8 hours of sleep feeling groggy and tired? You likely woke up in the middle of a Deep Sleep phase.
Human sleep works in 90-minute cycles. To wake up feeling refreshed, you need to wake up between cycles, not during them. Pixedra’s Sleep Cycle Calculator does the math for you, helping you time your alarm to coincide with your body's natural REM (Rapid Eye Movement) rhythm.
How to Find Your Perfect Wake-Up Time
- I want to Wake Up at... Enter your desired wake-up time (e.g., 7:00 AM). The tool will tell you the best times to fall asleep.
- I plan to Sleep at... Enter the time you are going to bed. The tool will give you the best times to set your alarm.
- Nap Mode: Choose "Power Nap" (20 mins) or "Full Cycle Nap" (90 mins) to recharge without ruining your night's sleep.
Note: "Sleep at" and "Nap Mode" features are coming soon.
The Science of Napping
Not all naps are created equal. Use our calculator to choose the right duration:
The Power Nap (20 Minutes)
Best for a quick energy boost. You stay in light sleep and wake up alert.
The Grogginess Zone (30-60 Minutes)
Avoid this. You enter deep sleep, and waking up now causes "Sleep Inertia" (feeling drunk/tired).
The Full Cycle (90 Minutes)
A complete reset. Good for making up for lost sleep, but requires more time.
Understanding Sleep Stages
What happens during a Sleep Cycle?
A typical cycle lasts 90 minutes and consists of:
- Light Sleep (N1 & N2): Your body relaxes. Easy to wake up.
- Deep Sleep (N3): Physical restoration. Very hard to wake up (Grogginess occurs here).
- REM Sleep: Dreaming and mental restoration.
Our calculator adds 15 minutes (average time to fall asleep) to ensure you hit the cycle perfectly.
Frequently Asked Questions
Morning Routine
Waking up early? Calculate your commute and morning costs with our Trip Fuel Cost Calculator.