On first look, a smart ring seems like the perfect product to track key health and fitness insights about yourself in the most discreet of ways. We’ve put some of the most popular through our rigorous and impartial lab tests to tell you if any are worth buying.
Like with a lot of newer tech products, smart rings don’t come cheap, and some have expensive subscriptions that you have to keep paying each month to track your activity.
Spending hundreds on a potential fad isn’t worth the risk, so we’ve tested the most important features found on smart rings. We’ve tested how accurate their heart-rate monitors, pulse oximeters, and daily step counts really are, as well as how easy the apps are to use and how often you’ll find yourself having to charge them. Read on to find out our results.
See how other wearables perform in our labs with our guides to the best smartwatches and best fitness trackers.
The best smart rings
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Date tested: December 2024 – May 2025. Page last checked: May 2025. We are not able to show every retailer and cheaper prices may be available.
We send more than 30 wrist-worn wearables to the Which? test labs each year. Find out our favourites in our smartwatch and fitness tracker reviews
The smart rings we tested
All the smart rings we tested are listed in alphabetical order below.
Only logged-in Which? members can view the best smart rings from our tests.
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Amazfit Helio ring
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Size and weight 3.65-3.82 grams; Available in three sizes (8-12); 23.7mm thick
Other tech specs Offers sleep tracking; 10ATM water resistance; Wireless charging cradle included; Compatible with iOS and Android phones
Need to know Measure your finger to choose the correct size before buying
Oura Ring Gen4
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Size and weight 3.3-5.2 grams; Available in 12 sizes (4-15); 25.7mm thick
Other tech specs Comes in six colours, some of which are more expensive than others (the silver and black versions are the cheapest); All Oura Rings currently require a subscription for the paired app (£5.99 a month at time of testing); Compatible with iOS and Android phones; Wireless charging cradle included
Need to know Order Oura’s ring-sizing kit to find the right size for you before buying
Also considering a more traditional tracker you wear on your wrist? Find out which type will suit you best in Should I buy a fitness tracker or a smartwatch?
Oura Ring Gen3
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Size and weight 4-6 grams; Available in eight sizes (6-13); 27.5 mm thick
Other tech specs Comes in two styles: ‘Heritage’ and ‘Horizon’, and we tested the Heritage style, which has a flat side on part of the ring instead of being fully rounded; Four colours to choose from; All Oura Rings currently require a subscription for the paired app (£5.99 per month at time of testing); Compatible with iOS and Android phones; Wireless charging cradle included
Need to know Order Oura’s ring-sizing kit to find the size for you before buying
Samsung Ring
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Size and weight 2.3-3 grams; Available in eight sizes (6-13); 23.3 mm thick
Other tech specs Available in black, silver or gold; Claimed water-resistance to a depth of 100 metres; Wireless charging cradle included; Only compatible with Android phones
Need to know Order Samsung’s ring sizer to find the size that gives you a secure fit when buying
How we test smart rings
Our smart ring tests are done by wearable-tech experts in the Which? labs. We anonymously buy all the products we test to keep our results impartial.
We regularly revisit the smart rings on sale to see if there are any more popular models that need testing.
Sensor accuracy
There are two main sensors on smart rings: the heart-rate monitor and the step tracker. To measure accuracy, our testers wear each smart ring while doing different activities – including running, cycling and carrying out household activities, such as loading the dishwasher and sweeping the floor. We find that the precision of monitors can vary significantly depending on the activity you are doing.
We compare the data from the smart ring to a trusted reference step-counter and chest-belt multiple times to see if the ring is overstating, understating, or hitting the accuracy mark.
Whether the smart ring is relying on GPS to track distance, or relying on steps, we check if it can tell us correctly how far you’ve travelled. We take each smart ring on routes of known distances (both walking and running), including open-sky areas and woodland areas to add the challenge of potential loss of GPS signal. We also test the accuracy of built-in blood pressure monitors and pulse oximeters if the smart rings offer these features.
App quality
When using a smart ring, you are highly reliant on the paired app to fill in your personal health data, start workouts, and check the analysis of your activity. Our testers spend weeks getting stuck into the accompanying phone app and assess if it’s easy to navigate without hassle and understand what the data is telling you.
Battery life
Our battery tests involve testing to see how long the smart ring should last during a typical day wearing the device. We will repeat the test with the GPS enabled (whether built-in or connected to a smartphone), as this is known to reduce battery times considerably on trackers. Note that some smart rings have batteries of different sizes depending on the size of the ring you choose.
Features
Smart rings generally offer a lot of fitness and health features. Our evaluation takes into account how many sports they claim to track, and whether they offer extra features such as sleep and menstrual tracking estimates.
Smart rings score breakdown
Other features that we test to make up our scores include the smart ring’s comfort, build quality and durability. We also test whether if it is a secure device: if we have any concerns about data privacy or security of a smart ring, we will tell you in our reviews.
Though these rings are ‘smart’, their smart features are almost non-existent compared with smartwatches. Smart features you find on smartwatches include receiving and responding to notifications from emails, social media and texts, as well as making calls and streaming music. If smart rings become more capable in the future, we will include these in our score breakdowns.
Here is the criteria that currently makes up our scores:
- 45% fitness
- 20% ease of use
- 10% battery
- 15% app
- 5% features
- 5% build quality.
Why you can trust us: at Which? we’re free from manufacturer and retailer influence. Find out more about our impartiality and how your support helps us to stay editorially independent
Are smart rings more accurate than fitness trackers?
There’s no inherent reason why smart rings should be particularly more or less accurate than fitness trackers. Our tests show that a smart ring is capable of offering sensors with very good accuracy. On the other hand, we’ve also seen models that can significantly under or overestimate – in one case by 41%. In terms of the activities you can track, there are both smart rings and fitness trackers that have a very long list of sports to choose from.
However, we’ve seen fitness trackers with very good accuracy for nearly a fifth of the price of some of the smart rings on sale. So it’s important to do your research before buying to make sure you don’t compromise your fitness goals and end up with an expensive dud.
What are the disadvantages of a smart ring?
The main drawback of smart rings is that you don’t have a screen to directly control the device without your phone. This means you rely on the paired app for pretty much everything. This includes choosing to start a workout that the ring can’t automatically detect, seeing your activity progress, checking your heart rate, and so on. You’ll likely find you have to take your phone when running to get the features you are after.
Another big drawback for the smart rings we have tested is that you cannot adjust their physical size. So if your finger size fluctuates, it’ll likely no longer fit or measure your activity properly.
Also, smart rings don’t have smart features yet so we’ll likely have to wait a while until a flick of your finger allows you to take calls, respond to texts or control music.
It’s early days for the smart ring industry and you don’t currently have lots of brands to choose from. Oura rings require a membership fee for the paired app, which was £5.99 a month when we tested it, and the ring’s functionality is incredibly limited if you don’t pay up.
What finger should you wear a smart ring on?
Generally, it’s best to wear a smart ring on your index, middle or ring finger. Whichever you choose, it’s more important to make sure it fits securely. In our testing we found that if the ring moves, the heart-rate monitor can stop working. The Samsung Ring and Oura Rings have sizing kits that you order to find the perfect size for you if you’re not able to try them on in a shop.
Are smart rings waterproof?
Generally, yes. But the level of water resistance can differ and it’s best to check in the small print. The ones we’ve tested so far all have a high enough water-resistance rating for diving as well as for surviving splashes and the rain. It’s also important to know that water resistance can lessen over time, but since smart rings don’t have screens, it is likely that they will stay robust.
Can you answer phone calls on a smart ring?
No, or rather not yet. A number of smartwatches have this feature, but smart rings lack microphones and speakers to have this feature.
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