Smart Sleep Cycle Calculator & Bedtime Planner

Wake up feeling refreshed and energized by aligning your sleep with your body's natural rhythms. Our Sleep Cycle Calculator is a science-based tool designed to help you find the optimal times to go to bed and wake up. It works by calculating your sleep in 90-minute cycles, helping you avoid waking up in the middle of a deep sleep phase, which can leave you feeling groggy.

How It Works

The calculator is designed around the principle that a good night's sleep consists of several complete 90-minute sleep cycles. It also smartly accounts for the average 15 minutes it takes to fall asleep. Our tool offers three flexible modes to fit your planning needs:

  1. Wake Up At: Tell us when you need to wake up, and we'll calculate the best times for you to go to bed.
  2. Sleep Now: Instantly calculate the best times to wake up if you were to go to sleep right now.
  3. Sleep Duration: Perfect for naps or planned sleep, this mode tells you when you'll wake up if you sleep for a specific amount of time.

Key Features

  • Based on Natural Sleep Cycles: All calculations are designed to help you wake up at the end of a 90-minute cycle, which is key to feeling alert and rested.
  • Three Calculators in One: Use the tabbed interface to easily switch between calculating your bedtime, your wake-up time from now, or the end of a planned sleep session.
  • One-Click Reminders: For any calculated time, you can click the bell icon to set a simple browser notification to remind you when it's time to sleep or wake up (requires your permission).
  • Accounts for Fall-Asleep Time: The calculator automatically adds 15 minutes to its calculations to account for the time it typically takes to fall asleep.
  • Detailed & Optimal Results: Provides several recommended times, not just one, showing how many sleep cycles you'll complete and the total duration of sleep.
  • User-Friendly Interface: A clean design with easy-to-use time pickers, a smooth scroll-to-results animation, and both Light and Dark modes.
  • 100% Private: All calculations are done in your browser. No personal data is ever stored or sent to a server.

How to Use This Tool

  1. Step 1: Choose Your Method
    Select the tab that matches your goal: "Wake Up At," "Sleep Now," or "Sleep Duration."
  2. Step 2: Enter Your Time
    For the "Wake Up At" and "Sleep Duration" modes, use the simple inputs to set your desired times. The "Sleep Now" mode works instantly.
  3. Step 3: Get Your Optimal Times
    Click the "Calculate" button. The results will show you several ideal times to go to bed or wake up.
  4. Step 4: Set a Reminder (Optional)
    Click the bell icon next to any result to request a browser notification for that specific time.

Find Our Tool

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