This online bedtime calculator will help you to find out the best time to fall asleep in order to wake up at a specified time and feel refreshed and alert. The calculator works by counting backwards in sleep cycles. Each cycle typically lasts about 90 minutes and repeats several times over the course of a night. Six best times to fall asleep are calculated and you can choose the one which best suits you. Just take into account that a healthy sleep for an adult consists of 7 – 9 hours (5 or 6 sleeping cycles) and that the average time to fall asleep is 14 minutes, so you have to be in the bed accordingly before the calculated bedtime. In case you want to find out the best time to wake up if you want to fall asleep at a specified time check our Sleep Calculator.
Best time to fall asleep
The two main categories of sleep are called rapid eye movement (REM) sleep and non-REM sleep, and each has a number of stages. Humans move through these stages in an almost regular pattern as they sleep, and a night sleeping means cycling through these stages a few times before waking up.
Non-REM sleep
• The first stage, also known as “transitional sleep”, during which the body and brain shift from a state of wakefulness to one of sleep. It’s relatively short and lasts only about five minutes. The sleep is fairly light and people may wake up from this stage of sleep more easily than from other stages.
• The second stage of non-REM sleep, also known as “light sleep”, is another stage of sleep when the human body starts transitioning to the deep sleep stage. This is the first stage of true sleep, lasting from 10 to 25 minutes. According to National Institute of Neurological Disorders and Stroke, humans spend most of the time during the sleep cycle in this stage of sleep.
• The third stage of non-REM sleep, also known as “deep sleep” or slow wave sleep, is the deepest stage of sleep, when brain waves are extremely slow. Blood flow is directed away the brain towards the muscles, restoring physical energy. It may be very difficult to awaken in this stage, and if you forcibly wake up, you don’t adjust right away and often feel groggy and disoriented for some time.
REM sleep
REM sleep is the fourth and final stage of the sleep cycle, the time to get there is approximately 70 to 90 minutes after falling asleep. During this stage of sleep, the eyes move rapidly behind the closed eyelids, the breathing shallows, and the heart rate and blood pressure increase. During this stage, the arm and leg muscles are paralyzed to prevent the body from acting. The REM stage is also when most dreaming occurs. This state is closer to the wakeful state than the other stages of sleep.
Sleep Cycle
Together, REM and non-REM sleep stages form a complete sleep cycle. Each cycle typically lasts about 90 minutes and repeats four to six times over the course of a night.
Waking up in the middle of a sleep cycle leaves you feeling groggy, tired and stressed out. The ultimate goal of this bedtime calculator is to help you wake up in-between the sleeping cycles so as to wake up alert and ready to start a productive and happy day!
Related calculators
Some recommendations on how to fall asleep quickly you can find in the information part following our Sleep Calculator.