Last updated on May 6th, 2019

How to Use the Sleep Cycle Calculator

Not sure how to use our sleep calculator? Follow these steps:

1.- Select one of the two following options:

A) I have to wake up at

B) I plan to go to bed at

2.- Enter in your bed or wake up time accordingly.

3- Click on “Calculate Bed Times” to obtain your results

The Sleep Cycle Calculator will then present a few options for a wake up/bedtime. These are based on the natural sleep cycles of the body during sleep.

Your Results Explained

Did you know that the secret to getting a good night’s rest isn’t getting a certain number of hours, but rather a certain number of cycles?

If you need a quick reference for sleep and want to see just how many cycles you can squeeze in during the night, our calculator provides quick reference. The goal is to complete as many cycles as shown in the suggested result without waking up in the middle of deep sleep.

While sleeping more than four hours at once is preferable, the calculator will give you more than one option for your rising time. Select any of the options to get full sleep cycles and awaken feeling more alert than if you were to awaken mid-cycle.

However, if you’re curious about the science behind sleep, read on to explore the ins and outs of resting up.

What Are Sleep Cycles and Why Should You Care?

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) SleepDefined 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 FourDelta waves and little movement in the eyes or throughout the body. Should not be interrupted. Also referred to as deep sleep.
Stage ThreeIdentified by the presence of delta waves, which signify slower brain activity which is thought to be restorative. Not easily interrupted.
Stage TwoThe longest sleep stage; encompassing 50% of all sleep. Eye movements stop and most brain activity slows to waves.
Stage OneLight 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 eight 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.

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.

Sleep Deprivation Symptoms
  • Falling asleep in sedentary positions, such as when watching television or in meetings
  • Low motivation
  • Frequent mood swings
  • Decreased ability to think and work
  • Exhaustion
  • Sadness or depression

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.