Sleep Calculator
Calculate the best times to fall asleep or wake up based on your biological sleep cycles. Waking up at the right time can make a massive difference in your daily energy levels.
How long are sleep cycles?
An average sleep cycle is approximately 90 minutes long. During this time, the brain moves through different stages of sleep, including light sleep, deep sleep, and REM (Rapid Eye Movement) sleep. Waking up at the end of a cycle, rather than in the middle of deep sleep, usually helps you feel more refreshed.
How much sleep do adults need?
Most adults require between 7 to 9 hours of sleep per night for optimal health and cognitive function. However, individual needs can vary. This calculator helps you plan for the recommended number of cycles to meet these requirements.
What is the "15-minute" rule?
The average person takes about 14-15 minutes to actually fall asleep after getting into bed. This calculator includes this time in its "Time to Bed" suggestions to ensure you complete your full sleep cycles.
Is it better to wake up earlier or sleep more?
Consistency is key. Waking up at the same time every day, even on weekends, helps regulate your circadian rhythm. It is generally better to wake up at the end of a 90-minute cycle even if it means slightly less total sleep, rather than waking up during deep sleep and feeling groggy (sleep inertia).