Last updated on December 28th, 2019
About Our Calculator
Sleepyhood.com’s Sleep Cycle Calculator is intended for informational purposes only. The calculator estimates the best time for adults (age 18-54) to wake up and go to bed. For further reference, we’ve also added sleep time recommendations by the National Sleep Foundation.
What Are Sleep Cycles?
The old adage of getting eight hours a night seems to give people the idea that sleep is all about hours. However, your body doesn’t rest in one consecutive span of time—but rather, in cycles.
The National Institutes of Health clarifies that sleep occurs in several cycles. After you fall asleep, your body will work through each stage of the cycle before repeating the process once again.
Stages of the Sleep Cycle
These five stages of the sleep cycle have been outlined by the U.S. Department of Health and Human Services and consist of the following:
|Rapid Eye Movement (REM) Sleep||Defined by vivid dreams and lots of movement in the eyes. Thought to be restorative. With each consecutive cycle, this REM stage lasts longer and longer, reducing the amount of time spent in stages three and four.|
|Stage Four||Delta waves and little movement in the eyes or throughout the body. Should not be interrupted. Also referred to as deep sleep.|
|Stage Three||Identified by the presence of delta waves, which signify slower brain activity which is thought to be restorative. Not easily interrupted.|
|Stage Two||The longest sleep stage; encompassing 50% of all sleep. Eye movements stop and most brain activity slows to waves.|
|Stage One||Light sleep. Slow movement and muscle activity. Can easily be interrupted and stopped. Often lasts 10 minutes or less.|
While the specific length of the sleep cycle varies from person to person, 90 minutes is fairly average. Since falling asleep can take up to a half hour depending upon the person, the old adage of eight hours makes a lot of sense. Eight hours of rest gives your body enough time to complete five cycles and often prevents entering the deeper stages of a new cycle before waking up.
Have you ever woken up on the wrong side of the bed or slept for a long time only to feel worse than when you’ve slept less? This is often due to waking up in the middle of a cycle. Since the sleep cycle gets progressively deeper as it progresses, waking up in the middle of a cycle will throw your body out of alignment and force it to disrupt the natural healing process of sleep.
That’s why it’s recommended to prioritize getting complete sleep cycles over getting a certain number of hours of sleep. Doing so will not only give your body the rest it needs to make it through the following day, but also give you a better start in the morning.
How Much Sleep Do I Need?
Discovering the number of cycles and hours of sleep you need to properly function during the day is crucial. After all, insomnia and exhaustion have been found to be more impairing than alcohol or other drugs in some cases.
The amount of sleep you need is heavily based on your age. For example, infants regularly need 16 hours of sleep a day to properly function and grow. Compare that to the recommended amount of sleep for adults—seven to nine hours. The key is to set proper sleeping habits in place and to understand the natural signs your body gives you to come up with the right number for you.
Sleep Time Recommendations
The National Sleep Foundation released the results of a world-class study that took more than two years of research to complete.
“The NSF has committed to regularly reviewing and providing scientifically rigorous recommendations,” says Max Hirshkowitz, PhD, Chair of the National Sleep Foundation Scientific Advisory Council. “The public can be confident that these recommendations represent the best guidance for sleep duration and health.” The panel revised the recommended sleep ranges for all six children and teen age groups. A summary of the new recommendations includes:
- Newborns (0-3 months): Sleep range narrowed to 14-17 hours each day (previously it was 12-18)
- Infants (4-11 months): Sleep range widened two hours to 12-15 hours (previously it was 14-15)
- Toddlers (1-2 years): Sleep range widened by one hour to 11-14 hours (previously it was 12-14)
- Preschoolers (3-5): Sleep range widened by one hour to 10-13 hours (previously it was 11-13)
- School age children (6-13): Sleep range widened by one hour to 9-11 hours (previously it was 10-11)
- Teenagers (14-17): Sleep range widened by one hour to 8-10 hours (previously it was 8.5-9.5)
- Younger adults (18-25): Sleep range is 7-9 hours (new age category)
- Adults (26-64): Sleep range did not change and remains 7-9 hours
- Older adults (65+): Sleep range is 7-8 hours (new age category)
What Happens If I Skip Sleep?
Skipping sleep, otherwise known as running a sleep debt, is a dangerous and fatiguing practice. Sleep debt is gathered when you deny your body the number of sleep hours and sleep cycles it needs in a night. For example, if you sleep for eight hours under normal conditions but only get five hours one night, you would have a sleep debt of three hours.
Just like with financial debt, sleep debt needs to be repaid. If you are unable to repay the debt, and don’t give your body time to make up for the sleep, signs of sleep deprivation will occur.
While self-diagnosing isn’t always accurate, sleep deprivation can be potentially dangerous and is something to look out for. If you or a loved one is exhibiting many of these signs and often doesn’t get enough sleep, chances are good that a sleep debt is involved.
Sleep debts can be taken care of in multiple ways. While it isn’t always preferable, if you have a day with little or nothing planned coming up on your calendar, consider sleeping without an alarm set to wake you up. Otherwise, you could budget in an extra hour of sleep into your schedule for the remainder of the week or month. Doing so will help you cut back on sleep debt and get back to a regular schedule.
Probably the best way to combat sleep debt is to set healthy sleeping habits in place now so that sleep debt cannot affect you later on.
Tips for Getting a Good Night’s Rest
Sleeping right means taking the time to plan your day around your nights. Provided you’ve taken the time to organize your schedule and have the ability to sleep as many hours as recommended for your age group, the following tips should keep you rested and rejuvenated:
First, remove depressants and stimulants from your evening routine—and possibly from the rest of your day. Energy drinks, coffee, and similar substances can be lifesavers when emergencies strike and you’re forced to skip sleep. While this is perfectly acceptable for the body for one or two nights a month, consistently stimulating your body during the hours before sleep will result in insomnia. A good rule of thumb is to put down the caffeine at least five hours before bed, which matches the half-life of the substance.
Next, you’ll want to play to your body’s natural predisposition to routines. If possible, set up a sleep schedule in which you lay down for bed at the same time each day—even on weekends. A sleep schedule tells your body to prepare for sleep at the right time, every time. You’ll feel tired near bedtime and alert when it’s time to wake up. Much like with stimulants, avoid habitually breaking your schedule to ensure it sticks with your body.
Finally, give your brain the safe space it needs for sleep by ensuring your resting environment is used for resting and that alone. Avoid using or entering your bedroom during the day, and make sure to invest in blackout curtains and cut off all of the lights at night. You also want to make sure the air in your room isn’t too humid or too dry, and that the air remains around 60-68 degrees Fahrenheit.
All of the above aids in ensuring you can sleep well and maximizes the value of the sleep calculator. From cutting out stimulants to laying down the groundwork for rest, there are many tools you can use to optimize your rest to enjoy more energy during the day.
Jose is a digital marketing entrepreneur who was frustrated by his own experience of finding a good neck pillow online. After tossing and turning from many nights of restless sleep, he created sleepyhood.com to help others in similar situations get a restful good night sleep.