Sleep Calculator — Find Your Best Bedtime & Wake-Up Time
Use this sleep calculator to find the best time to go to bed or wake up based on your natural sleep cycles.
No signup required. Get instant results.
What do you want to calculate?
Selected wake-up time: --:--
Selected bedtime: --:--
This mode estimates your best wake-up times if you go to sleep now.
Choose a time that fits your schedule.
These times are based on 90-minute sleep cycles to help you wake up between cycles, not during them. Most adults feel best with about 5–6 full cycles per night.
Know when you’re sleeping and want ideal wake times? Wake-up time calculator →
How this sleep calculator works
Enter your time, and this calculator uses 90-minute sleep cycles to suggest bedtimes or wake-up times so you wake up between cycles—not during them.
Each sleep cycle is about 90 minutes, and a good night’s sleep is usually 5–6 full cycles.
FAQ
What is the best time to go to sleep? The best time depends on your wake-up time and completing full sleep cycles. This calculator helps you find an optimal schedule.
How many hours of sleep do you need? Most adults need about 7–9 hours of sleep, which equals roughly 5–6 full sleep cycles.
Is this medical advice? No, this is a planning tool only.
Why do results cross midnight? Bedtimes are calculated backward from your chosen wake-up time.
Does this include time to fall asleep? Yes, the sleep-now mode includes a short 15-minute fall-asleep buffer.
Which option is best: 4, 5, or 6 cycles? Aim for 5 to 6 full cycles when possible; 4 cycles is a shorter night.
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