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Calculating your body's natural sleep cycle

Knowing your body's sleep cycle can provide better quality sleep.
Knowing your body's sleep cycle can provide better quality sleep.

In accordance with my previous article, “It’s not always the amount of sleep you’re getting - it’s the quality” I talked about how completing full sleep cycles each night provides the quality of sleep needed for good health. In this article, I thought I’d explain how to calculate your individual sleep cycle in order to get the best rest possible during this busy season.

It's really easy to figure out how long your natural sleep cycle is too. All you have to do is look at the clock right before you fall asleep, then again when your body wakes up naturally. It’s best to calculate your sleep cycle on the weekend, or when you have a few consecutive days where you don’t have to wake up to an alarm.

Once you’ve determined how long your body has slept naturally, you then divide the amount of time you’ve slept by the 90-110 min time range it usually takes a person to complete the full restorative cycle. From this you’ll get the average number of sleep cycles you’ve completed.

For example-
if your body falls asleep naturally at 11:30 pm and then wakes up naturally at 8:30 am, you've slept for a full 9 hours. If you divide that 9 hours by 90 minutes (the average time it takes to complete the sleep cycle) you can see that you’ve slept for 6 complete cycles.

Using this information you can train your body to wake up exactly when your alarm is supposed to go off.
If you know it takes your body 90 minutes to be fully rested then you can determine when it’s the best time for you to go to bed and still wake up at the time you’re supposed to.

Now you have to understand that everybody is different. Individual bodies have different needs so the 90 minute interval is only a ball-park figure. After trying this naturally falling asleep/waking up method I was able to figure out that my natural sleep cycle is around 96 minutes. Knowing that I wake up at my best after sleeping for 96 minutes, I know the best time for me to go to bed when I have to wake up at a certain time.

I know that going to bed at 11:30 pm and waking up at 9 am is more beneficial for me than going to bed at 10:30 pm and waking up at 9. If I were to fall asleep at 11:30, I would be able to complete 6 full sleep cycles (give or take a few minutes), but if I were to fall asleep at 10:30 my cycles would become interrupted. I would complete 6.5 sleep cycles and wake up at a time when my body doesn’t want to wake up. In this instance, less sleep is better.

Ever wake up mid-deep sleep and feel groggy the entire day? It’s because you’re sleep pattern has been interrupted and you’re body wasn’t ready to start the day. By determining you’re natural cycle, you can achieve better sleep and wake up feeling refreshed.


  • Ryan Franczek 5 years ago

    meg you're the best!! every morning i wake up and can't wait to log in and see what new articles you have posted!! keep up the good work :)

  • Rebecca King 5 years ago

    This is a very insightful article. Thanks for plethora of knowledge. You're articles are always on the top of my reading list!

  • Lala 5 years ago

    I remember when you did this study at school!

  • Profile picture of Chris Hugh
    Chris Hugh 2 years ago

    Nice article. I linked to it.

  • Profile picture of Chris Hugh
    Chris Hugh 2 years ago

    Nice article. I linked to it.

  • Corrine 11 months ago

    But how did you calculate that you need 96 minutes per cycle? That's what I need to know

  • Corrine 11 months ago

    Also can you explain your math more clearly for those who are mathematically challenged. I don't see how you divide 9 by 90 and get 6. I get .1

  • Christopeher 10 months ago

    First you need to match the units (hr/min).

    60min = 1 hour
    90min = 1 Sleep Cycle

    convert 9 hours to mins. 9x60 = 540min.
    so you have 9hrs = 540min.
    now you divide 540min by 90 min. 540/90 = 6.
    So, now you have 6 Sleep cycles completed.