MySleepCalculator.app

    Sleep Cycle Calculator

    Use the calculator below to find sleep and wake times that align with your natural 90-minute sleep cycles. Each cycle includes light sleep, deep sleep, and REM; waking at the end of a cycle reduces morning grogginess.

    Sleep Calculator: Find Your Perfect Bedtime and Wake-Up Time

    Calculate sleep times using 90-minute sleep cycles and set a quick browser alarm from your results.

    Sleep Calculator

    Calculate the perfect bedtime or wake-up time based on your sleep cycles. Each cycle lasts about 90 minutes (90-minute cycles), and waking up at the end of complete cycles helps you feel more refreshed. Get sleep advice for a good night's sleep with 5-6 cycles.

    Mobile Optimized

    Mobile-First Design

    Optimized interface that works perfectly on all screen sizes

    Fast Loading

    Instant calculations with no waiting time

    Offline Capable

    Works even without internet connection

    Touch Friendly

    Large buttons and easy-to-use time pickers

    📱 Add to Home Screen for App-Like Experience

    Sleep Calculator

    Choose your preferred calculation method and enter your wake up time or bedtime in AM/PM format. Get personalized sleep recommendations based on 90-minute cycles and complete cycles for a good night's sleep.

    ⏰ Web Alarm

    Set a browser alarm for your wake-up time. Keep this tab open to make sure the alarm can trigger.

    💡 How This Works

    Enter your desired wake-up time, and we'll calculate the best bedtimes based on complete 90-minute sleep cycles. This helps you wake up at the end of a cycle when you feel most refreshed.

    What Is a 90-Minute Sleep Cycle?

    A sleep cycle is roughly 90 minutes and includes Stage 1–2 (light sleep), Stage 3 (deep sleep), and REM. Most adults need 5–6 complete cycles per night. Our calculator helps you schedule sleep so your alarm goes off at the end of a cycle instead of in the middle of deep sleep.

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