Oura Ring 4 Sizing Kit – Size Before You Buy The Oura Ring 4 – Unique Sizing, Not Standard US Ring Sizes – Receive Credit for Purchase
$10.00



Price: $10.00
(as of Nov 15, 2025 01:02:20 UTC – Details)
The Oura Ring 4 Sizing Kit allows for you and those around you to find the ideal fit before purchasing. With a sizing kit purchase, a 10 credit will automatically be applied to your Oura Ring 4 at checkout. A properly fitting Oura Ring 4 will result in the highest possible data accuracy, comfort, and overall experience. Oura Ring 4 sizes are slightly different from standard ring sizes, so it is important to size yourself using our tools and to follow our sizing instructions. Oura Ring 4 works on all fingers and can be worn on either hand. For optimal accuracy, we recommend wearing your Oura Ring 4 on your index, middle, or ring finger.
OURA RING 4 SIZING KIT – The Oura Ring 4 Sizing Kit is the ideal way to find the perfect size. It’s a custom sizer that allows for you, and those around you, to find the perfect fit before purchasing
SIZE BEFORE YOU BUY – Oura Ring 4 sizes are different from standard ring sizes. Size yourself with the Oura Ring 4 Sizing Kit. For additional details, see “From the brand” section below
NOT STANDARD SIZING – Oura Ring 4 sizes are slightly different from standard ring sizes, so it is important to size yourself using our Oura Ring 4 Sizing Kit. Oura Ring 4 is available in sizes 4-15. There are no half sizes
COMFORT AND ACCURACY – A properly fitting Oura Ring will result in the highest data accuracy, comfort, and overall experience
CHOOSE A FINGER – Oura Ring 4 works on all fingers and can be worn on either hand. For optimal accuracy, we recommend wearing your Oura Ring 4 on your index, middle, or ring finger. Size the exact finger you plan to wear your Oura Ring 4 on
HOW IT SHOULD FIT – Oura Ring 4 should fit securely and comfortably at the base of your finger. Your ring should not rotate as you go about normal daily tasks. We recommend wearing your ring sizer for at least 24 hours to confirm your best fit

Margo –
If you’re into tracking your health – this ring is for you !
I absolutely LOVE my OURA ring , it gives me great insight into my sleep and heart health as well as keeping track of my activity levels and stress levels , it warns me when it senses something wrong & notifies me , as well as , giving me suggestions on how to improve those said things . All and all I highly recommend getting one for yourself . My ring is silver as it goes better with my skin tone & because it’s cheaper 😂 it looks like a normal ring . It fits well , is comfortable , I only take it off to shower or when I’m doing hard work with hands like gardening to prevent it from getting damaged of scratching . The battery lasts a long time, it is very lightweight, pretty self explanatory with set up .
Anastasiia Kysel –
Great and Easy Way to Find the Perfect Fit
I’m so glad I ordered the Oura Ring 4 Sizing Kit before buying the actual ring. The kit arrived quickly, and it includes several sample rings in different sizes so you can test which one feels most comfortable. I wore a couple of sizes for a day each to see how they fit during sleep and daily activities. It really helped me avoid guessing the wrong size. Very convenient, simple to use, and definitely worth it before purchasing the real Oura Ring!
Natalie –
Great HSA/FSA investment to monitor your health journey!
It provides lots of great data and personalized information based on the data. I use it mainly for tracking sleep. I have found it helpful when it detects a change in my average temperature when I am starting to feel rundown and under the weather. The visual notification gives me the push to try and get better sleep and take care of myself. I am a few months in and while there are small scratches on the ring it doesn’t bother me.
Avid Reader –
1) Ōura Ring Sizing Kit / 2) Ōura Ring 4 Reviews / 3) Addendum Item
Amazon, despite complaints, views the Ōura Ring Sizing Kit as the same or a similar item as the Ōura Ring 4, itself… thus, two DIFFERENT reviews AND ratings for two COMPLETELY DIFFERENT products.————–1) THE ŌURA RING SIZING KIT / 5-StarsŌura states that the Ring 4 sizes are NOT the same as traditional ring sizes.I did NOT break out my Ring Sizing Loops to determine the veracity of that statement because the cost, of the Ring 4 Sizer, on Amazon is applied as a credit towards the cost of an Ōura Ring 4 WHEN purchased via Amazon.I will say that there is perhaps a little difference, compared to traditional ring sizes, but I’m not sure that it’s much because I ended up with the ring size that I thought would work.Interestingly enough, size 10 that I expected for the middle finger was a perfect fit for the Index finger, which is normally a traditional 9… so there is some difference in the sizing and I wholeheartedly recommend procuring the Ōura Ring 4 Sizer BEFORE purchasing the Ōura Ring 4.NOTE that the Ōura Ring 4 Sizer does not work for all Ōura Ring models, so anyone deciding to purchase a previous iteration of the Ōura Ring, due to cost decrease and/or a Sale, will need to utilize the correct Ōura Ring Sizer for the model ring chosen.If there is a question of Sale or Discount Pricing, due to the delay from checking ring sizes, then I suggest an online Chat with Amazon Customer Service representative to make sure that you can lock in any discounts to use after verifying the correct Ring size.FYI – Ōura recommends wearing the sizing ring on the finger that will bear the ring, in order to become accustomed to the ring size/feel and to see how well it fits throughout a normal day.I followed that advice and I believe that everyone should do the same.—————-2) Ōura Ring 4 / 1-StarFirst, even with the ring sizing kit and wearing the sizer non-stop until the Ring 4 arrived, the size of the Ring 4 in only whole sizes proved inadequate. My hands clearly fluctuate enough in size to be an issue, regardless of the finger or hand that is used.Next, the heart rate (HR) was always available and showing in the app, signifying that the Ring 4 was measuring the HR, HOWEVER, the app called to show the graph of the HR for over two (2) weeks, meaning there was no history nor any assessment available.Next, the Sleep function, even with learning curve, seemed to function out of the box, HOWEVER, after the first recharge of the Ring 4, there was an issue with accurately recording start and stop points of Sleep AND eventually the app would show No Sleep Data AFTER uploading/updating UNTIL THE NEXT day. There was no event showing for sleep ALTHOUGH the Ring 4 clearly annotated the Start of the Sleep period the previous night.Next, even after more than three (3) weeks of use, the app has failed to graph the Blood Oxygen Saturation, in spite of showing the data observed and available to see at any given moment. Again, I find this to be very odd and indisputably useless to the user.Next, the App is full of “flash” or substance but in terms of a quick overall view of all the numbers, like most Apps, no such uncluttered view can be found. While the plethora of information and links is appreciated, the search to locate immediate data numbers across all items is tedious, frustrating and unappreciated.To provide an analogy, it’s like having to read an entire book to search for and locate the Synopsis of the book. For those who aren’t into books, then it’s like watching a TV and THEN SEEING the Preview for the show that you just watched.I and most users seem to prefer a Table of Contents approach where the Raw Data is shown and then you can click to go to the Analysis, Assessment and Suggestions for that particular Biometric.In short, the App’s interface is beautifully flashy and showy but about as useful up front as a Show Pony on a crop farm.That makes it overwhelming, even to those who are focused readers and moreso to the vast majority who are not.Finally, many details and assessments are NOT available for anywhere from four (4) weeks to three (3) or more months.While understandable, it makes it impossible to fully assess the personal value and utility of the Ring 4 in the 30-day period for returns.That means that the $400+ ring and the annual subscription fee is only acceptable for those with money to burn, so to speak, because all of the shortcomings or issues, even if expandable and temporary, outweigh the cost of what is actually a pretty doggone accurate piece of tech wear, resulting in the clear choice to return the ring.AND… there is one other issue to consider which is that if your hands swell, perhaps from work, or shrink, perhaps from weight loss, then your $400+ ring AND subscription become useless… until you purchase another Ōura Ring that does fit.Based on my research and experience, there are equally accurate smart fitness watches with solid Apps and reasonable insights and suggestions based on the assessment of the biometrics.Also, there is another smart ring on the market that appears to rival the Ōura Ring in accuracy, provides an seemingly identical App for all appearances seen, comes as an adjustable ring using the same high-end materials and sensor setup AND which additionally boasts being approved and classified as a Medical Grade Device, instead of a Consumer Grade Device.All of that at a far, far lower cost AND the same updates, assessments, insights and suggestions BUT with NO subscription fee.That being said, I am a Go/No-Go tester of products meaning things are either 5-star or 1-star with enough details for people to decide that my 1-star item might be good enough to be their 3- or 4-star item.The Ring 4 failed to make the grade for my needs nor was it able to justify keeping the ring to see if things improved or the money was worth the extended wait for certain observations, but it was remarkably accurate when comparing data to manual results, such as HR, SpO2, etc.There is no blood pressure data, for those in search of BP function. I am not sure that BP could be accurately obtained below the wrist at this point in technology, but maybe in the future.REMEMBER that when returning an Ōura Ring, you MUST also CANCEL the Ōura App Subscription as it is a separate financial issue from the purchase.The subscription is free for the first 30-days and a part of setting up your account before you are able to use the App, so it’s an easy thing to forget.3) Addendum — there is a charging cable organizer with a carabineer that works GREAT for the Ōura Ring 4 charging station and cable that is available on Amazon AND IS HIGHLY RECOMMENDED.That is my next review and it will be 5-Stars.It was kind of a why-the-heck-not afterthought purchase that became an INSTANT 5-Star Should Have item as soon as I unpackaged it!!!!
JR –
Great customer service.
This was a gift for our daughter, after about a year or slightly less, the battery would not last more than a few hours. She contacted the manufacturer and they sent her a brand new one can’t say enough about this company. I can’t speak to what information it collects for you with that’s probably available through the website.
jabba –
Update: Great Customer Service! (Stopped working after a few Months)
So I spent a good dollar on this, and it was very excited the first few months using it. Worked great track my sleep, heart rate the whole bit.A few months later, it started acting funky and didn’t like to pair with my phone. I did nothing different. I didn’t get a new phone.Now it’s at the point where it will not pair at all I’ve tried putting on the base and went through all the troubleshooting. For $400 this thing should last more than a year.UPDATE: I contacted Oura and they are sending me a replacement. From a customer service aspect they were fantastic. I am just hoping my ring was a random issue and this will not persist where the lifespan is just a few months. It is a great product when it’s working.
Abbie –
I love my Rose Gold Oura!
I know the Oura Ring comes at a steep price but I truly think it is worth it. I have had it since February and I only ever take it off to charge it. The biggest con is that the rose gold coating has a few chips on the outer edges and I have scratched it up pretty good. I have put this ring through a lot though so I’m not that surprised. You can buy clear silicone “cases” for it but it dulled out the brightness of the color itself. I still get compliments on how pretty it is even though I have been rough with it. The first week wearing it was an adjustment. At first it felt heavy and bulky but after the second week I stopped noticing it. I got a size 8 and it’s the perfect fit and feels comfortable. It doesn’t ever slip off but it’s easy to remove. My main reason for getting the Oura Ring was to help me keep track of my cycles and ovulation. I love the app and everything it has to offer. Overall the quality is great and I recommend this ring to all of my family and friends.
Liberty –
Der Oura Ring 4 ist ein ausgezeichnetes Fitness- und Gesundheitstool. Er ist sehr leicht, angenehm zu tragen und am Finger kaum spürbar – ideal für den Alltag und den Schlaf. Die App überzeugt mit übersichtlichen Auswertungen, detaillierten Gesundheitsdaten und hilfreichen Empfehlungen. Insgesamt ein hochwertiges Produkt, das Design, Komfort und Funktion perfekt kombiniert.
Miko –
Amazon で購入後、3ヶ月ほどでバッテリー周りの不具合に遭遇しました。症状としては充電台から離すとすぐにスマートフォンとのペアリングが解除されてしまうというものでした。Oura Ring のヘルプセンターの右下にチャットボットがあり AI なのでありきたりな回答なのかと思えばそうではなく- 症状を入力- 普段使用している Oura アプリのアカウントのメールアドレスを聞かれるので入力。該当メールアドレス宛に確認メールが来るので承認- 交換対象製品を確認 & 交換品の送付先を入力という、ほぼ 3 ステップで交換対応の申請が完了し、1時間程度で無料扱いの注文完了メールが届きました。指輪タイプのデバイスはバッテリー周りの不具合遭遇率が高く懸念していましたが、スムーズに交換対応が行えたのでとても良かったですし、これぐらい交換対応がスムーズなのであれば月々払っている Oura の高額なサブスク代も半額分ぐらいは Apple Care みたいな保険代だと思えば割と納得感があるなと今回のトラブル発生から一連の手続きで思いました。
Amazon カスタマー –
後で判明したがアマゾンとその他で1000円近く値段が違う。類似の商品にも出て来なかった。24時間装着とあったので着けて寝たら、かぶれでしまった。本商品とは素材が違うが、高いので怖くて買えない
Miss Chansigaud –
I hesitated for a while before investing in this gadget. And I love my Gadgets! but after doing some homework on the competition, I decided to jump for it.First, the fit and metal colour are great, I couldn’t be happier, the quality and durability is insane, i do everything with it, I rarely take it off.The connectivity to my Samsung Z Fold6 was flawless, no hiccups, plus, everything you open the app, it updates in no time. so great compatibility.Now, you need to give it time to gather data about you, of course… it will not happen overnight which is quite right, but the intel you get afterwards is great.Your body age, sleep quality, energy available, your stress, it is such a great little ring. it is a lot of money for such a small device but the value for money is worth it.I highly recommend it if you are curious and want to be nudge in the right direction for better health.
Ula –
Najlepszy tracker samopoczucia i dobrostanu