Sleep Calculator
Find best bedtimes & wake-up times based on 90-minute cycles.
15 min
Sleep tips
A Sleep Calculator helps you discover the optimal bedtime or wake-up time based on 90-minute sleep cycles. Unlike focusing only on total sleep hours, it ensures you wake up at the end of a sleep cycle, leaving you refreshed and energized.
A typical sleep cycle lasts about 90 minutes, and a healthy night’s sleep includes 4–6 cycles. Our free online sleep calculator takes your desired wake-up or bedtime and calculates the best times to sleep or wake up by aligning with these cycles. Simply input your time, and the tool does the rest!
Q: How many hours of sleep do I need?
Most adults need 7–9 hours, but completing full 90-minute sleep cycles matters more than just hours.
Q: Is waking up after 4 or 5 sleep cycles okay?
Yes, 4–6 cycles are ideal. Waking at the end of a cycle is better than interrupting one, even if you sleep longer.
Q: Does the sleep calculator work worldwide?
Absolutely! Our tool adjusts to your local time and works seamlessly on desktop, mobile, or tablet, anywhere in the world.
Try our free Sleep Calculator today to optimize your sleep cycle and wake up feeling your best!