How to Measure Sleep | Get to Know the Oura Sleep Score

September 5, 2017

At Oura, we believe that sleep is one of the main pillars of health, just as important as diet or exercise. Sleep removes toxins from your brain, which is one of the reasons why it is necessary in helping your body to recover. A chronic lack of sleep can trigger a wide array of health issues such as obesity, heart disease, diabetes, and high blood pressure. We should be allowed to monitor our sleep just like our food intake and our activity.

What You’ll Learn in This Article

  • What are the challenges in measuring sleep?
  • How does Oura meet these challenges?
  • What is the Oura Sleep Score and what are its sleep contributors?

The Problem: How to Measure Sleep

The problem with sleep monitoring is that most people (outside of sleep clinics) don’t have the tools with which to track sleep accurately. We do have hunches of how we slept when we wake up, but sleep still remains somewhat invisible to us. For example, without a measuring device, we cannot really know whether we had enough deep or REM sleep. Moreover, how many of us remembers how we slept, say, a couple of weeks ago? Knowing it would be helpful, though, because our “sleep history” can have a significant effect on our readiness today. We can also misinterpret our sleep quality: having a feeling that you slept like a log doesn’t necessarily mean that your sleep was especially restorative.

If we don’t know what our sleep quality is, we cannot act proactively. In the very worst case, this can lead to a situation where we start to learn more about our sleep only after we’ve developed some sort of a severe sleeping disorder and need to consult a sleep clinic. While the sleep professionals can really dig deep into sleep, it is usually examined only for a night or two. Many sleep tracking devices are also quite uncomfortable to wear.

Even though most of us don’t suffer from the worst forms of sleeping disorders, we all face the problem that we don’t have accurate, long-term data of how we sleep and how our sleep quality affects us.

To summarize, we face problems in:

  • Measuring our sleep accurately
  • Getting long-term data regarding our sleep

Tracking Sleep With the Oura Wellness Ring

One of the biggest motivations to develop the Oura ring was to offer a reliable, convenient, and usable solution to measure and analyze sleep quality. We here at Oura understand that sleep is nothing to be joked about, and therefore Oura’s sleep staging algorithms are based on years of scientific research. They are also independently validated by SRI International.

We want you to be able to get insight about your sleep every day and throughout the year(s). The Oura ring is therefore unobtrusive in its sleep tracking: it doesn’t disturb your sleep, but quietly measures body signals such as your resting heart rate (RHR), heart rate variability (HRV), respiration rate, body temperature, and movement with highly accurate sensors. (Read more about the ring technology).

Using the collected data, Oura can help you to qualify your sleep every night, and also in the longer term. The Oura app and Oura Cloud show you your sleep metrics in an easy-to-read format and with visualizations. You’ll also get guidance on what the different metrics mean and on ways to improve your sleep quality over time.

I know how to be active and eat healthy, but I’ve never been really good at recovering and getting enough sleep. This is why Oura has been my number one choice.
– Nelli Lähteenmäki, CEO of Fifth Corner Inc. Watch the video.

The Sleep Score

The core measure of your sleep is your daily Sleep Score – a metric that is based on several sleep-related contributors that Oura tracks both in the short and long term. The score ranges from 0-100%, and as a rule of thumb: the higher it is, the better, more restorative sleep you had.

Daily sleep metrics in the Oura app

Do remember that the human body is very complex, and you and your sleep are unique. Don’t focus too much on any one sleep contributor, but follow the Sleep Score in conjunction with your own feelings of how refreshed or tired you are. Comparing your score with other people isn’t useful for you, either.

What Oura Tracks to Help You Measure Your Sleep

Below are the contributors Oura uses to calculate your Oura Sleep Score. Next we’ll go through why they’re important and what you can learn from them.

Total Sleep

This contributor shows you the total amount of sleep you achieved the previous night, including light, REM and deep sleep. Note: here we speak about actual sleep – the total time you spent in bed does not necessarily equate with the amount of total sleep. Even though the amount of sleep one needs is individual, most adults require between 7-9 hours of sleep per night.


Put simply, efficiency means the percentage of time you spent sleeping while in bed. The longer the bar, the more efficient your sleep was. Hypnograms in the Oura app and Cloud show you in more detail when you were awake, and when sleeping. In general, a sleep efficiency score of 85% or above shows that you fall asleep quickly enough (in less than 20 minutes) and don’t wake up too often during the night. Again, do remember that your sleep habits are individual, and it’s for example perfectly normal that when you get older, you might wake up more often during the night – it’s just one of those things we may need to accept.


Tranquility is the other side of the efficiency coin. It tells you the total time you spent awake. Disturbances such as wake-ups, get-ups and restless time during your sleep can have a big influence on your sleep quality, resulting in less restorative sleep. They can be one of the reasons behind daytime sleepiness, for example. Obviously, many things can cause your sleep to be interrupted, but things such as stress, noise, sleep buddies, light, room temperature, infections, or late-time activities (exercise, screen time, heavy meals) are on the list of potential suspects.

REM Sleep

REM is short for rapid eye movement. This is the stage of your sleep that is associated with dreaming, but also with memory consolidation, learning and creativity. In other words, this is the stage that energizes your mind. The amount of REM sleep one gets varies a lot, between nights and between individuals. However, it usually makes up about 20-25% of your total sleep time. Oura shows you both the total amount of REM sleep you got, and in the hypnogram also the times when you were in the REM sleep stage. Note that the amount of REM sleep is one of the things that can decrease with age.

Deep Sleep

Deep sleep is considered the most restorative and rejuvenating stage of sleep. This is the stage where your muscles repair and growth takes place, your body is relaxed, your blood pressure is lower, and it’s also harder to wake you up. The amount of deep sleep varies between nights and individuals – on average, adults spend some 15-20% of their total sleep time in deep sleep (with age, you’ll probably get less deep sleep). It’s said that regular physical activity and avoidance of stuff such as heavy meals and alcohol before bedtime or long naps and caffeine in the afternoon can increase the amount of deep sleep.

Sleep Latency

This is the amount of time it takes for you to fall to sleep. Again, sleep latency is highly personal, but a rule of thumb is that it shouldn’t take you more than 15-20 minutes to fall asleep. There are many factors that might lead to a decrease in your sleep latency. Exposure to too much blue light, a late dinner and/or alcohol too close to bedtime are among those. Bear in mind that dozing off in less than 5 minutes can also indicate something, most commonly that you haven’t slept enough the previous night.

Sleep Timing

Every human has a biological clock which is aligned to day/night cycles. All of our essential biological processes such as body temperature, hormone releases and hunger operate on 24-hour cycles known as the circadian rhythms. There are differences in our rhythms, though. Some of us are more morning-oriented, some are evening people, and others somewhere in-between. Regardless of the orientation, having consistency in your rhythm is important. From a sleep quality point of view, having the midpoint of your sleep be somewhere between midnight and 3am is also preferred.

Light Sleep

In addition to the contributors above, the Oura Ring also measures the third stage of your sleep, Light sleep. Even though it’s not one of the Sleep Score measures per se, it is included in the Total Sleep contributor. And it’s there for a reason, since light sleep is not in any way insignificant. First of all, we usually spend almost half of our total sleep time in light sleep. It’s also the stage which typically starts our sleep cycle, and prepares our bodies to transitions between different sleep stages throughout the night.

If you’re interested in tracking your sleep but don’t yet have the tools for it, have a look at the new Oura ring in the Oura Shop. If you have an Oura ring, have a look at our Sleep FAQ for more answers or dig deep into your data in Oura Cloud.

Heart rate variability or HRV is something you can track with the Oura ring but what is HRV all about and why should we care?

Oura solution
© 2020 Oura. All Rights Reserved.