Oura Ring 5 Review: The Smallest Smart Ring, and the Membership Behind It

The headline number is a volume reduction. Oura says the Ring 5 is 40 percent smaller than the Ring 4, with a width of 6.09 mm, a thickness of 2.28 mm and a weight starting at 2 grams depending on size. For comparison, a plain titanium wedding band is usually between 4 mm and 8 mm wide, so the Ring 5 now sits inside the range people already wear without thinking about it. That matters more than it sounds. Earlier smart rings failed a simple test: they caught on pockets, pressed into the neighbouring finger when you made a fist, and dug in when you carried a bag. Samuel Gibbs, who wore a size 8 for several weeks for the Guardian, reports that the Ring 5 clears all three and that the black finish still looked new at the end. One reviewer over a few weeks is thin evidence on durability, but it is the only sustained account available so far. The case is titanium with a scratch-resistant PVD coating, and the interior is titanium too, which matters for anyone who reacts to nickel. Oura offers six finishes. The sensors now sit in low-profile domes on the inner surface, visible in the images here as three small windows. Gibbs notes they protrude slightly but are not noticeable in wear. One caution remains. A ring you forget you are wearing is also a ring you can forget to take off, and Oura rates the Ring 5 to 100 metres, so water is not the risk. Losing it is.

The sensor set is straightforward. Red and infrared LEDs read blood oxygen. Green and infrared LEDs alternate for heart rate, heart rate variability and respiration rate. A digital sensor follows temperature trends, and an accelerometer handles movement. From those four inputs Oura derives more than 50 metrics across sleep, activity, readiness, stress, heart health and women's health. Oura makes two accuracy claims on the product page: 99 percent heart rate correlation against ECG, and 95 percent sleep staging accuracy against a clinical sleep lab. Both deserve care. The sleep staging figure is footnoted to a 2021 paper in Sensors that studied an earlier Oura ring against polysomnography. It did not include the Ring 5. The heart rate figure links to Oura's own accuracy blog post. Neither is an independent test of this generation, so both are recorded here as Oura's claims. What can be said with more confidence is what a finger-worn sensor is good at. Resting measurements taken overnight, when your hand is still, are the strongest case for this form factor. Readings taken while you are moving fast are the weakest, which is why the workout side of the ring leans on your phone. Gibbs found exactly that: the Ring 5 detects more than 40 activity types automatically, but for distance, pace and route it depends on the phone in your pocket, and it does not replace a running watch. Read the scores as ranked signals rather than clinical measurements. A readiness score of 88 is Oura telling you that today looks better than your own recent baseline. It is not a diagnosis, and Oura does not present it as one.

The ring collects, the app interprets, and the membership pays for the interpretation. Without a membership the Oura App keeps only basic current metrics. Scores, trends, long-term analysis, Symptom Radar and the Oura Advisor chatbot all sit behind the subscription. Oura includes one free month with a new ring, and publishes the ongoing monthly price on its membership page. The current figure lives in the offers block on this page, because subscription pricing changes and prose does not. The app itself is the strongest part of the package, and that is not a small thing to say about software. It is organised into three views. Today surfaces one thing worth acting on, such as a resting heart rate sitting above your baseline. Vitals breaks out seven categories with your normal range alongside today's figure. My Health takes the long view, ranking sleep, cumulative stress and heart health on a scale from needs care to thriving. Gibbs describes the analysis as comprehensible without a statistics background, and specifically praises the explanations attached to each metric. Oura Advisor is a chatbot built on your own data. It cannot tell you the weather, and it will not answer questions outside your health record. Within that boundary Gibbs found it useful for spotting long-term trends. The arithmetic buyers should do is simple. A ring bought outright is a one-time cost. A membership is not. Over three years the membership can approach the price of the ring itself, and if you stop paying, the hardware keeps recording but the app stops explaining. That is the single most important thing to understand before buying.

Compatibility is narrower than the marketing suggests, in two different ways. The first is your phone. Oura's support documentation is specific: the app needs iOS 16 or higher, or Android 11 or higher with Google Play services, and the phone must support Bluetooth 5.0. Android 11 arrived in 2020, so most phones in current use qualify, but a Huawei handset without Google Play services does not, and neither does an older tablet kept as a bedside device. Check this before buying. The second is your country. Several of the newer features roll out one market at a time. Oura's announcement states that Blood Pressure Signals reaches the United States, India and the United Arab Emirates first. Gibbs notes that Health Radar, which adds overnight blood pressure and breathing disturbance monitoring, launched in the United States in June. The app interface itself is available in more than twenty languages, so the language barrier is lower than the feature barrier. The practical consequence is that two people buying the same ring in different countries do not get the same product. A buyer outside the launch markets gets the hardware and the core analysis, and waits for the rest. Oura has not published a dated rollout schedule that could be verified here, or said when a given market gets a given feature. On the data side, the ring stores readings and syncs over Bluetooth Low Energy, firmware updates arrive automatically through the app, and the ring supports an airplane mode for anyone who would rather it stopped transmitting.

Oura rates the Ring 5 at six to nine days on a charge, and the spread is not marketing vagueness. A larger ring has more room for cells, so battery life rises with ring size. A size 6 sits near the bottom of that range and a size 13 near the top. The only independent figure available comes from the Guardian. Gibbs measured a size 8, the third smallest available, at just short of eight days, and described that as roughly two days more than the equivalent Ring 4. That result sits comfortably inside Oura's range, which is a useful sign: the claim is not stretched. Charging uses a size-specific dock supplied in the box, together with a USB-C cable. Oura quotes about 80 minutes for a full charge, and Gibbs recorded under 90 minutes, which is close agreement. A charging case is sold separately and is not included. Oura says it holds about a month of additional battery and can put a full day back into the ring in ten minutes. Gibbs puts the case at up to five full charges. The habit that suits this ring is not a weekly charge but a daily top-up. Ten minutes on the dock while you shower is enough to keep it permanently ahead, and it avoids the one real gap in the ring's coverage, which is the night it spends off your finger.

Two limitations sit at the end of this ring's story, and both are easy to miss at the point of purchase. The first is sizing. Oura's sizing page states that the Ring 5 comes in sizes 6 to 13, where the Ring 4 ran from 4 to 15. That is a real narrowing at both ends, and Oura also says the redesigned interior fits differently from the Ring 4, so an existing owner cannot order the same size again. Oura supplies a sizing kit of plastic replicas, and Gibbs recommends wearing one for several days, because finger size moves with temperature and time of day. Fit is not a comfort question here. A loose ring gives worse data, because the sensors need consistent skin contact. The second is the end of life. The Ring 5 cannot be repaired and its battery cannot be replaced. Gibbs flags this and deducted a star for it. When a sealed lithium cell stops holding a useful charge, and every one eventually does, the ring is finished. Oura offers free recycling, which handles disposal responsibly but does not change the outcome. Gibbs also notes the ring contains no recycled material. Set against a titanium band that looks like jewellery, that is an odd proposition. The object is built to outlast you and the electronics inside it are not. Anyone weighing this against a smartwatch should notice that many smartwatches do have replaceable batteries through a service channel, and factor a replacement cycle into the cost. Our scoring method explains how a limitation like this feeds into the final figure.