Healthy Sleep Cycles

Calculate better bedtimes and wake times with 90-minute sleep cycles, calming sounds, and configurable bedtime reminders.

Stop waking up groggy. Sleep Cycles calculates your optimal bedtime and wake time based on natural 90-minute sleep cycles.

THE PROBLEM Ever slept 8 hours but still felt exhausted? That's because you woke up mid-cycle. When your alarm interrupts deep sleep, you experience "sleep inertia" - that foggy, disoriented feeling that can last for hours.

THE SOLUTION Sleep Cycles times your wake-up to occur between cycles, when you're in light sleep. The result? You wake up naturally alert and refreshed, even with less total sleep.

HOW IT WORKS

1. Open the app when you're ready for bed
2. See 6 optimal wake times based on 90-minute cycles
3. Pick the time that fits your schedule
4. Wake up between cycles, not during them

FEATURES

Sleep Cycle Calculator Calculate the perfect wake time based on when you want to sleep. Adjust your personal fall-asleep time (5-60 minutes) for accurate results.

Smart Recommendations Times within the optimal 7.5-9 hour range are highlighted, so you know which gives you the best rest.

16 Ambient Sounds Relaxing background sounds to help you fall asleep faster: rain, ocean, stream, fireplace, night sounds, white noise, pink noise, brown noise, and more. Sounds stream from the app's CDN and can be downloaded in the app for offline use.

Sleep Timer Set sounds to automatically stop after 5-120 minutes. Fall asleep without draining your battery.

Bedtime Reminders Optional daily reminders help you start winding down and go to sleep on time.

WHY SLEEP CYCLES IS DIFFERENT

Free Forever No subscriptions. No paywalls. No "premium" features locked behind payment. Everything works from day one.

Privacy First No account required. No data collection. No tracking. Your sleep habits stay on your device, period.

Simple & Lightweight No complex sleep tracking. No sensors. No Apple Watch required. Just science-based calculations that work.

THE SCIENCE BEHIND IT Sleep happens in cycles of approximately 90 minutes. Each cycle progresses through light sleep, deep sleep, and REM (dream) sleep. Waking during deep sleep triggers sleep inertia. By timing your alarm to coincide with light sleep between cycles, you avoid this entirely.

PERFECT FOR

• People who wake up tired despite sleeping enough
• Students optimizing study and rest schedules
• Shift workers managing irregular patterns
• Anyone wanting better sleep quality
• Nappers who want to wake refreshed

No subscriptions. No accounts. No tracking. Just better sleep.

Download Sleep Cycles and wake up refreshed tomorrow.