Reverse Sleep Calculator
When Should I Go To Bed?
Tell us when you want to wake up, and we'll tell you the best times to fall asleep. Based on natural 90-minute sleep cycles to help you wake up feeling energized.
You should aim to fall asleep at one of these times:
These times are based on completing full 90-minute sleep cycles. We've also factored in the average 15 minutes it takes for a person to fall asleep.
Beat Sleep Inertia: The Reason You Wake Up Tired
Ever slept for 8 hours but woken up feeling like you barely slept at all? The culprit is likely Sleep Inertia.
Sleep inertia is the groggy, disoriented feeling you experience for several minutes (or even hours) after waking up. This happens when your alarm clock abruptly pulls you out of a deep stage of sleep, like Slow-Wave Sleep (SWS), instead of a lighter sleep stage.
Your body sleeps in cycles, each lasting about 90 minutes. During a cycle, you move through different stages of sleep, from light to deep and back to light again. The ideal time to wake up is at the end of a sleep cycle, when your body and brain are naturally in a lighter state of sleep.
Our Wake Up Refreshed Calculator does the work for you. By calculating backwards from your desired wake-up time, it identifies the perfect moments to go to bed. This ensures you complete a full 4, 5, or 6 sleep cycles, dramatically increasing the chances you'll wake up feeling alert, refreshed, and ready to start your day.