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How It Works: The Science of a Great Night's Sleep
Our bedtime calculator isn't based on guesswork. It uses the science of 90-minute sleep cycles. A typical night's sleep consists of several cycles through different stages of sleep, including light sleep, deep sleep, and REM sleep. Waking up at the end of a cycle, rather than in the middle of one, is the key to avoiding sleep inertia (that groggy, morning-after feeling).
Find Your Perfect Sleep Schedule
Whether you need to wake up at 6am for work or want to find the best time to go to bed, our tool helps you build a better sleep schedule. By aligning your sleep with your body's natural rhythms, you can optimize your sleep cycle and improve your overall well-being.
Frequently Asked Questions
How long is a human sleep cycle?
A complete sleep cycle typically lasts about 90 minutes. Our calculator uses this as a baseline to recommend the best times to wake up.
Is it better to wake up during light sleep?
Yes. Waking up during a light sleep stage, which usually occurs at the end of a 90-minute cycle, helps you feel more alert and refreshed than being woken up from deep sleep.
How much sleep do I really need?
Most adults need 7-9 hours of sleep, which corresponds to 5-6 full sleep cycles. Our tool shows you options for 4, 5, and 6 cycles so you can choose what works for you.