Bedtime Calculator
Enter your desired wake-up time below and get science-based bedtime options based on 90-minute sleep cycles. Waking at the end of a complete cycle helps you feel refreshed instead of groggy.
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
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.
Why Use a Bedtime Calculator?
Your optimal bedtime depends on when you need to wake up and how many sleep cycles you want (typically 5–6 for adults). Our calculator adds 15 minutes for the time it takes to fall asleep, then shows bedtimes that align with the end of complete 90-minute cycles so you wake during light sleep.
Related Sleep Tools and Guides
- Wake Up Time Calculator for finding your best wake-up options.
- Sleep Cycle Calculator to understand full-cycle timing.
- What Time Should I Go to Sleep? complete guide.