Oura Ring 3 v Circul+: Battle of the smart rings

Is Circul+ a better ring to track your health stats compared to Oura? Here's our take.
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Two of the best smart rings you can pick up right now are the Oura Ring 3 and the Prevention Circul+. Both pack in big sensors into small form factors and promise to track various elements of your health and fitness.

We've freed up some digit space for both rings to live on recently to get a sense of what these rings have to offer and whether there's one you should get on your finger over the other.

Here's a bit of breakdown of what to expect from the two rings and the one we'd pick to keep wearing.

This is our look at how the Oura Ring 3 (full review) compares to the Prevention Circul+ (full review).

Oura Ring 3 vs Circul+: Pricing

Before getting into all things hardware and software related, how much are these smart rings going to cost you? Both rings are priced at $299, but with the Oura Ring 3, you'll also have to pay up for a subscription to access your data. The Circul+ uses a free app and cloud service to store your data in.

That Oura Ring subscription service costs $5.99 a month, which isn't a massive amount, but if you've already paid up front for the ring and already stomaching a whole host of other monthly subscriptions, it can start to add up.

So, long term, the Circul+ is cheaper.

Oura Ring 3 vs Circul+: Design and comfort

Oura Ring 3 v Circul+: Battle of the smart rings

Bottom line, one of these rings looks like and fits like a normal ring and the other one doesn't.

The one that does fit like a normal ring is the Oura. The sensors are well hidden away underneath a sleek, titanium design that comes in four different looks. It does require a sizing kit to make sure you get the best fitting size option but it's elegant, stylish and feels lovely to wear.

You do need to make sure you need to give the sensors a wipe every now and then and as you can probably see from our images, the ring isn't immune to scratches if you don't take it off as recommended for activities like lifting weights.

You can wear it in the shower and swim with it thanks to the 100m water resistant rating.

Oura Ring 3 v Circul+: Battle of the smart rings

The Circul+ isn't a fully circular ring and comes in just one matte black look and is available in three sizes to accommodate most ring sizes. It's not very pretty and isn't fit to wear in the water either, but the IP65 water and dust resistance rating mean it does offer some durable protection.

The ring though does just feel a bit awkward to wear but is easy to put on and take off thanks to the spring loaded mechanism built-into the design.

Unlike the Oura, you notice it's always on and it's not a wearable that you can forget about, even after a few days of wearing it. It's a better fit for wearing at night, but again, the Oura feels more comfortable for all day and night wear.

It's a resounding win for Oura on the design, comfort and looks like a ring you'd want to wear departments.

Oura Ring 3 vs Circul+: Health tracking features

Oura Ring 3 v Circul+: Battle of the smart rings

When it comes to serious health monitoring features, there's only one winner here - the Circul+. It has the sensors on board to track heart rate, SpO2, temperature and also supports the ability to take single lead ECG readings and blood pressure readings.

The Oura Ring 3 in contrast doesn't include serious health monitoring features in the same way that an Apple Watch or Samsung Galaxy Watch does. So, there's no ECG or blood pressure tracking. Nothing that is included and could be considered health features carry any sort of regulatory approved to deliver serious health insights.

The Circul+ doesn't have that either, but Bodimetrics, the health tech company behind it, says the ring has been medically tested and built to work reliably on different skin tones.

The Oura Ring 3 can also track heart rate, heart rate variability, body temperature and will be able to monitor SpO2 levels when Oura turns the feature on.

There's a clear difference in the approaches of how Oura and the Circul+ use those sensors and the information and data that they can provide.

Oura Ring 3 v Circul+: Battle of the smart rings

Oura Ring 3 app

Oura uses them to give you a better sense of what it calls Readiness. It looks at aspects like heart rate, temperature, HRV, activity and sleep to tell you whether you're ready for a strenuous day or you should consider taking it easy.

The Circul+ takes a far more straightforward approach. It will track heart rate and SpO2 in real-time and can continuously monitor those data points as well, but you have to manually turn on the continuous monitoring. With the Oura, you simply put it on and let it automatically track.

If you want to take an on the spot ECG and blood pressure reading, you'll need to first calibrate the ring with data from a cuff-style blood pressure monitor before you can start capturing readings.

Oura Ring 3 v Circul+: Battle of the smart rings

What we've found with both rings first of all, is that the accuracy of the data felt very good. Both offered good resting and real-time heart rate data, and the Circul+ offered good SpO2 data, which the Oura currently lacks support for.

We found that while ECG and blood pressure readings weren't 100% accurate compared to another ECG and blood pressure device, it wasn't far off on most readings on the Circul+.

All of that data Circul+ captures is simply presented in the companion app with sets of graphs to view trends and drops and spikes in your data. You can also share that data to health professionals if needed. You're not getting any of the actionable insights or information to tell you whether you're ready for your day. It's about presenting you with the raw data and letting you choose what to do with it.

That approach of simply lay out the big health data may be what some people want. If you're looking for a more guided approach that puts the data into perspective and context, that's where the Oura excels.

Oura Ring 3 vs Circul+: Fitness and sleep tracking

Oura Ring 3 v Circul+: Battle of the smart rings

Both of these rings can track elements of your fitness and will monitor sleep time too.

The Circul+ keeps things very basic on the fitness tracking front, recording step counts and calories burned. Historical data isn't presented in the app and there's nothing like inactivity alerts or reminders to tell you to keep moving. You can also turn on a continuous heart rate tracking mode when you're doing some exercise, but the awkward design of the ring made it very difficult to wear during exercise.

The Oura Ring 3 offers a bit more on that front, but it's by no means a perfect fitness tracker. It will count steps, track distance, calorie burn, offers inactivity alerts and displays your daily movement inside of the companion app. It can also automatically recognise exercise and will eventually offer the ability to track heart rate during exercise. This data is all used to shape the overall Readiness score you see at the start of your day. The ring is comfortable to wear for exercise and we've used it for both runs and swims with no issue.

Oura Ring 3 v Circul+: Battle of the smart rings

For sleep tracking, we'd say both perform pretty well on that front. Again, with the Circul+, you'll need to turn on the continuous monitoring mode to get the richest level of sleep tracking, which offers sleep duration, latency, sleep stage breakdown, heart rate, SpO2 and temperature.

The Oura offers rich sleep tracking too, capturing sleep duration, sleep stages, sleep efficiency, heart rate and HRV for a measurement of stress.

We'd say the sleep tracking abilities of these two rings are quite evenly matched. Core data like sleep duration and time slept offered similar data. It was a similar story for heart rate as well. The Circul+ additionally gives you SpO2 and temperature data and graphs, so there's more raw data to dig into.

The Oura and Circul+ are both solid sleep trackers, but when it comes to fitness tracking, the Oura comes out on top.

Oura Ring 3 vs Circul+: Battery life

Oura Ring 3 v Circul+: Battle of the smart rings

If you want the ring with the most battery life and the best charging setup, it's the Oura Ring you want.

It promises 4-7 days battery life and that's exactly what it's capable of delivering. The Circul+ in comparison can muster up 16 hours of continuous monitoring, so it can't make it through an entire day and as we found out, you almost have to make a choice between tracking continuously during the day or at night, which isn't exactly ideal.

When you do need to charge, the Circul+ uses a small charging setup that can directly plug into a USB charging port, but the connection between the charging points and the ring make it challenging a lot of the time to get it sitting correctly to charge.

It's an entirely different story for the Oura Ring 3, where the cradle lets you essentially throw the ring onto it like hoop toss and it will start charging no problem.

Oura Ring 3 vs Circul+: Verdict

So, which of these smart rings should you go for? One promises to track your body and recovery to help you make better decisions about what you do in your day. The other is capable of tracking and measuring big health data that could help you closely monitor your health wherever you are.

If we had to pick one ring, it's the Oura Ring 3 we'd opt for. Yes, it can't track ECG or blood pressure like the Circul+, but as a package there's a lot more to like. The design is nicer and can be worn 24/7. The battery is better and there's also some useful health insights that feel useful and insightful albeit they lack any sort of regulatory approval.

The Circul+ offers much more raw health data and tracks it with a great degree of accuracy. The design and the disappointing battery life make it a tough one to recommend unless you really want something to track those rich health metrics mainly during sleep.

TAGGED Garmin Wearables

How we test

Michael Sawh


Michael Sawh has been covering the wearable tech industry since the very first Fitbit landed back in 2011. Previously the resident wearable tech expert at Trusted Reviews, he also marshaled the features section of T3.com.

He also regularly contributed to T3 magazine when they needed someone to talk about fitness trackers, running watches, headphones, tablets, and phones.

Michael writes for GQ, Wired, Coach Mag, Metro, MSN, BBC Focus, Stuff, TechRadar and has made several appearances on the BBC Travel Show to talk all things tech. 

Michael is a lover of all things sports and fitness-tech related, clocking up over 15 marathons and has put in serious hours in the pool all in the name of testing every fitness wearable going. Expect to see him with a minimum of two wearables at any given time.

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