Optimize Your Sleep Cycle

Wake up refreshed by timing your rest with your body’s natural 90-minute rhythms.

Why Timing Matters

Duration isn't the only factor in a good night's rest. Waking up mid-cycle—during deep sleep—causes "sleep inertia," leaving you groggy regardless of how many hours you logged. This tool pinpoints your light sleep windows so you can wake up feeling alert and energized.

How to Use This Tool

• Plan your wake-up time: Enter your desired wake-up time to see the best moments to head to bed.
• Calculate for "Sleep Now": If you're heading to bed immediately, check the list to see when to set your alarm for the easiest wake-up call.
• Adjust for "Sleep Latency": It takes the average person about 15 minutes to drift off. Customize the offset to match your personal routine.
• Start a countdown: Pick a window and use the built-in timer to manage your wind-down or wake-up routine.

FAQ

Is every sleep cycle exactly 90 minutes? Not quite. While 90 minutes is the average, individual cycles typically range from 80 to 110 minutes. Use these results as a baseline and adjust by 5–10 minutes if you still feel sluggish.

How much sleep do I really need? Most adults thrive on 5 to 6 cycles (7.5 to 9 hours). While you can survive on 4 cycles (6 hours) occasionally, consistent sleep deprivation leads to "sleep debt" and reduced cognitive performance.

The Science: The "Golden 90"

The first 90 minutes of sleep are the most restorative. This "Golden Period" contains the deepest non-REM sleep, where the body repairs tissue and the brain clears metabolic waste. Avoiding interruptions during this initial phase is vital for long-term physical and neurological health.