Oura Ring Sleep Tracking: How Accurate Is It Really?

The Oura Ring is a smart ring that tracks your health and sleep. It is part of a small but growing category of ring-shaped health trackers. The ring provides detailed stats, trends data, and a mostly hands-off experience in a much smaller size than a smartwatch. The Oura Ring has been praised for its accuracy in tracking sleep and health data, but some users have questioned the accuracy of its sleep stage classification. The ring is lightweight and comfortable to wear day and night, with a battery life of about a week. It is priced at $299, with an additional subscription cost of $5.99 a month or $69.99 a year for full data history and detailed sleep analysis.

Oura Ring's accuracy in tracking sleep

The Oura Ring is a smart ring that tracks your health and sleep. It is a small, lightweight, and discreet piece of jewellery that provides detailed stats, trends, and data about your sleep. It is a good alternative for people who do not want to wear bulky smartwatches or fitness trackers.

The Oura Ring has been praised for its accuracy in tracking sleep. A study published in ScienceDirect found that the Oura Ring did not differ significantly from the polysomnography (PSG) for the measures time in bed, total sleep time, sleep onset latency, sleep period time, wake after sleep onset, time spent in light sleep, and time spent in deep sleep. The Oura Ring had a sensitivity of 94.4%–94.5%, a predictive value for sleep of 95.9%–96.1%, and accuracy of 91.7%–91.8%. Another study published in PMC found that the Oura Ring accurately detected "light" and "deep" sleep in 65% and 51% of the epochs, respectively, and REM sleep epochs 61% of the time.

However, there are also some concerns about the accuracy of the Oura Ring. Some users have reported discrepancies in the data, with the ring underestimating or overestimating sleep by up to 30 minutes or even an hour. The ring also had limitations in detecting wake, as defined by PSG. Additionally, the Oura Ring may not be as accurate for people with inconsistent sleep schedules or those who routinely have "on the fence" nights, where they get close to, but not quite, enough sleep.

The Oura Ring has also been praised for its comfort and ease of use. It has a long-lasting battery life of about a week and charges relatively easily. The brand also provides a free sizing kit to ensure a snug and secure fit.

How does Oura Ring's technology work?

The Oura Ring is a smart ring that collects data on over 20 biometrics, including sleep, activity, and readiness. It has three sensors that listen to your body's signals: Infrared photoplethysmography sensors (PPG) for heart rate and respiration, a Negative temperature coefficient (NTC) sensor for body temperature, and an accelerometer for movement.

The PPG sensors in the Oura Ring are similar to those found in select hospital devices used to monitor heart rate. The system sends light through LEDs and receives it with a photodiode that captures how pulses of light through your arteries reflect your heart's activity. The ring samples 250 times per second and is 99.9% reliable compared to a medical-grade electrocardiogram (ECG). The PPG sensor also yields a high-fidelity reading of signals from your heart, including resting heart rate, heart rate variability, and respiration.

The NTC sensor monitors your nighttime skin temperature and can detect changes as small as 0.1° Celsius. This information can indicate how well your body is recovering, if you're coming down with an illness, or if hormones in your body are at work.

The Oura Ring also has an accelerometer that captures your everyday activity and workouts, such as walking or running. It provides updates on your activity progress and reminds you to get up and move after long periods of inactivity. For workouts that are more difficult for accelerometers to capture, such as yoga or elliptical training, the Oura Ring allows you to manually enter activities or import information from a third-party app by syncing with Apple Health or Google Fit.

In terms of sleep tracking, the Oura Ring has been found to be highly accurate in several reviews and studies. It can record heart rate variability and resting heart rate, make a good guess at when the wearer is awake or asleep, and a less accurate guess at the different stages of sleep. In a validation study of 96 participants, the Oura Ring showed good agreement with polysomnography (PSG) for global sleep measures and time spent in light and deep sleep. It underestimated sleep efficiency by 1.1%–1.5% and time spent in REM sleep by 4.1–5.6 minutes. The ring had a sensitivity of 94.4%–94.5%, a specificity of 73.0%–74.6%, and an overall accuracy of 91.7%–91.8%.

Comparison with other sleep trackers

The Oura Ring is a popular sleep-tracking device that offers a range of features and benefits to its users. When compared to other sleep-tracking devices, the Oura Ring stands out in several ways.

Firstly, in terms of accuracy, the Oura Ring has been found to provide highly accurate sleep data. In one study, the Oura Ring was compared to polysomnography (PSG), a multi-night ambulatory sleep measurement method. The results showed that the Oura Ring did not differ significantly from PSG in terms of time in bed, total sleep time, sleep onset latency, sleep period time, wake after sleep onset, time spent in light sleep, and time spent in deep sleep. Additionally, the Oura Ring had a high sensitivity and specificity for sleep measurement, with an accuracy of 91.7% to 91.8%.

When compared to other wearables, such as the Apple Watch Series 9 and Samsung Galaxy Watch 7, the Oura Ring has been found to provide the most accurate sleep data. This is because the Oura Ring is a more subtle and comfortable option, allowing users to track their sleep without the bulkiness of a wrist-worn device. Its HRV tracking is also highly accurate, with a 98.4% accuracy rate when compared to an electrocardiogram.

However, the Oura Ring may not be the best choice for active individuals who want to track their workouts and movements comprehensively. While it provides accurate heart-rate data, its activity tracking has been found to need improvement. Additionally, the Oura Ring requires a subscription to access most of the data, which can be an additional cost for users.

Overall, the Oura Ring is a discreet, comfortable, and highly accurate sleep-tracking device that provides detailed insights into sleep patterns and general health stats. When compared to other sleep trackers, it stands out for its accuracy, ease of use, and comprehensive data, making it a popular choice for those seeking a subtle and informative sleep-tracking solution.

User experiences and reviews

Many users have praised the Oura Ring's sleep tracking accuracy

Cost and value for money

The Oura Ring costs $299 for the third generation and $350 for the fourth generation. The fourth-generation ring also has an upgraded Smart Sensing technology with improved sensors and accuracy. The cost of the ring can go up to $500 depending on the colour chosen. The company offers a subscription for $5.99 a month or $69.99 a year, which provides access to more data, including detailed sleep analysis, blood oxygen sensing, stress insights, resilience scores, and dynamic activity.

The Oura Ring is more expensive than many sleep and fitness trackers on the market. For example, the Apple Watch Series 9 and Samsung Galaxy Watch 7 track similar data and do not require a subscription. The Garmin Forerunner 165 is another cheaper alternative at $249, which is better for outdoor fitness tracking. The Ultrahuman Ring Air ($349) and the Samsung Galaxy Ring ($399) are two other ring-shaped health trackers that are similarly priced to the Oura Ring.

Despite being more expensive, the Oura Ring has some advantages that may make it a valuable purchase for some users. Firstly, it is much smaller and sleeker than smartwatches, which may appeal to those who do not like wearing bulky devices on their wrists. Secondly, it has a long battery life of five to six days on a single charge, which is more convenient than other wearables that require more frequent charging. Thirdly, the Oura Ring provides highly accurate heart-rate monitoring and solid information on sleep cycles. The ring's HRV tracking is also surprisingly interesting and accurate, indicating physical and emotional stress. Finally, the Oura Ring is comfortable to wear all day and night, and it can be used to collect deeply personal health metrics and insights.

However, there are some drawbacks to the Oura Ring that may impact its value for certain users. Firstly, it struggles to log exercises and track workouts accurately, which may be important for those primarily seeking a fitness tracker. Secondly, the subscription cost may be an additional burden, especially when compared to other devices that do not require a subscription. Lastly, some users have found the ring uncomfortable, especially those who are not used to wearing rings.

Overall, the Oura Ring may be worth the cost for those who value accurate sleep tracking, a sleek and comfortable design, and a long-lasting battery. However, for those primarily seeking a fitness tracker or looking for a more affordable option, there are other devices on the market that may provide better value for money.

Frequently asked questions