Sleep Calculator
Find the best time to sleep and wake up to feel refreshed. Based on 90-minute sleep cycles.
Why Waking Up is Hard (And How to Fix It)
Ever woken up feeling groggy and tired, even after a full night's sleep? The problem isn't just *how long* you sleep, but *when* you wake up. Your sleep is made up of 90-minute cycles. Waking up in the middle of a deep sleep cycle causes "sleep inertia," that awful groggy feeling. This calculator helps you avoid that by timing your alarm to go off at the end of a natural sleep cycle, increasing your chances of waking up feeling alert and refreshed.
How to Use the Sleep Calculator
The calculator works in two ways:
- Plan Your Bedtime: If you know when you need to wake up, enter that time. The calculator will suggest several bedtimes that align with your sleep cycles.
- Plan Your Wake-Up Time: If you're ready for bed now, click the button to see the best times to set your alarm for a refreshing wake-up.
Our calculation includes an average of 14 minutes for you to fall asleep, giving you a more realistic bedtime.
Frequently Asked Questions (FAQ)
Q: How many sleep cycles do I need per night?
A: Most adults feel their best after completing 5 or 6 full 90-minute sleep cycles, which translates to 7.5 to 9 hours of sleep. This calculator provides options for 4, 5, and 6 cycles.
Q: Is the 14 minutes it takes to fall asleep accurate?
A: 14 minutes is a widely cited average for healthy adults. If you know it takes you longer or shorter, you can mentally adjust the recommended bedtime accordingly.