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OURA

Oura Ring 4 Sizing Kit - Before You Buy the Unique Sizing, Not Standard US Sizes - Receive Credit for Purchase, Sizing Kit, Oura App

  • Based on 3,674 reviews
Condition: New
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$8.49 Why this price?
4th of July Sale · 15% off was $10.00

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  • – 4-month term
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Availability: In Stock.
Fulfilled by Amazon
Arrives Tuesday, Jul 7
Order within 19 hours and 45 minutes
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Style: Sizing Kit


Color: Sizing Kit


Size: Sizing Kit


Features

  • 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

Description

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.

Special Feature: Heart Rate Monitor, Activity Tracker, Sleep Monitor


GPS: No GPS


Shape: Round


Brand: OURA


Style: Sizing Kit


Color: Sizing Kit


Compatible Devices: Smartphone


Display Type: No Display


Band Material Type: Stainless Steel


Water Resistance Level: Water Resistant


Additional Features: Heart Rate Monitor, Activity Tracker, Sleep Monitor


GPS Geotagging Functionality: No GPS


Band Material Type: Stainless Steel


Water Resistance Level: Water Resistant


Supported Application: Fitness Tracker, Sleep Monitor


Water Resistance Depth: 100 Meters


Closure Type: Push Back


Shape: Round


Style Name: Sizing Kit


Color: Sizing Kit


Display Type: No Display


Warranty Type: Limited


Brand: OURA


Model Number: JZ98-54870


Built-In Media: Oura Ring 4 Sizing Kit


Warranty Description: 1 Year Manufacturer


Wearable Computer Type: Smart Ring


Manufacturer: Oura


Cellular Technology: Not Supported


Compatible Devices: Smartphone


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Jul 7

This item is non-returnable:

Final sale - No returns

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Similar Products

Top Amazon Reviews

    • Accurate Sizing, Helpful Trial Period, and Worth It Before Buying the Ring Accurate Sizing, Helpful Trial Period, and Worth It Before Buying the Ring
Style: Sizing Kit Color: Sizing Kit Size: Sizing Kit
Review Image by Natalia
Review Image by Natalia
Review Image by Natalia
Review Image by Natalia
Review Image by Natalia
Review Image by Natalia
I purchased the Oura Ring 4 sizing kit because I didn’t want to guess on sizing for a $300+ health device, and I’m very glad I didn’t skip this step. The sizing kit is well-designed and closely mimics the look and feel of the actual ring. Oura recommends wearing a test ring for at least 24 hours. Still, I found it helpful to wear mine for several days to account for normal fluctuations in finger size (sleep, activity, temperature, etc.). This made a noticeable difference in choosing the correct size. One of the biggest benefits is accuracy. I typically wear a size 7 in rings, but after testing, I found a size 6 fit best for the Oura Ring. Without the kit, I likely would have ordered the wrong size. The fit of the actual ring matched the sizer exactly. I also appreciated being able to test the ring during real-life conditions. I wore it during work shifts that involved frequent handwashing, hand sanitizer use, and repeated glove changes, and it held up well. That gave me confidence in both the sizing and the practicality of wearing the ring daily. Another advantage is saving time. Purchasing the sizing kit separately allowed me to determine my size right away and order the ring without waiting for the standard sizing process (which can add a couple of weeks). For anyone eager to receive their ring sooner, this is a helpful option. The kit includes a small credit toward the ring purchase, which helps offset the cost slightly. While the kit itself may seem expensive for what it is, the value comes from avoiding sizing mistakes and delays. Minor note: the sizer felt slightly bulkier/heavier than the actual ring, but not enough to impact sizing accuracy. Overall, this is a practical and worthwhile step if you’re considering the Oura Ring, especially if your ring size varies or you want to be confident in your purchase before committing. ... show more
Reviewed in the United States on April 7, 2026 Reviewed in the United States on April 7, 2026 by Natalia
    • Perfect Sizing Kit for Oura Ring Perfect Sizing Kit for Oura Ring
Style: Sizing Kit Color: Sizing Kit Size: Sizing Kit
Review Image by Made
Review Image by Made
This sizing kit made it so easy to find the perfect Oura Ring size before ordering. The sample rings are comfortable, accurate, and helped me avoid choosing the wrong size. I appreciated being able to wear the sizing ring throughout the day to make sure it felt right. Simple, convenient, and definitely worth using before purchasing the actual ring. Highly recommend! ... show more
Reviewed in the United States on May 31, 2026 Reviewed in the United States on May 31, 2026 by Made
    • Oura ring sizing done correctly.
Style: Sizing Kit Color: Sizing Kit Size: Sizing Kit
The Oura ring the sizing rings prevented me from ordering the wrong ring size Oura ring. Remember the finger to wear the Oura ring for the best read out is your index finger. The fit needs to be snug but not too tight. Also, to make sure of proper fit, wear the ring sizing ring at least 24 hours. Worth the $10. ... show more
Reviewed in the United States on May 9, 2026 by Effie Rodriguez
    • Helpful before buying the actual ring
Style: Sizing Kit Color: Sizing Kit Size: Sizing Kit
This sizing kit is a great idea if you’re considering the Oura Ring. It helps you test different sizes and get a better feel for the fit before committing to the actual ring. I ended up returning it since I didn’t move forward with the purchase, but the kit itself was easy to use and useful for figuring out sizing. Definitely recommended if you want to be sure before buying the ring! ... show more
Reviewed in the United States on April 19, 2026 by KikaBrazil
    • A Must have!
Style: Sizing Kit Color: Sizing Kit Size: Sizing Kit
Dont skip these. They're vital in determining not only size but also which finger you want the ring located. I originally wanted it on my pointer but after wearing this tester I realized it would only get in the way at work and also for whatever reason, my pointer finger would be more swollen every morning and ring would be stuck. The ring finger worked the best overall. ... show more
Reviewed in the United States on May 8, 2026 by Janis Jade
    • Check the fit carefully. It needs to be snug
Style: Sizing Kit Color: Sizing Kit Size: Sizing Kit
The Oura ring is an Interesting tool for helping monitor your sleeping and movement throughout the day. Sizing requires buying these sizer rings which I did and the size 11 fit my two ring ringers. The 12 fit my index and middle fingers. I went with the 11. But the left was called little bit loose, not quite snug enough and occasionally does not sense pulse. Othe right ring finger is bigger as it is my dominant hand and works well there. But it is critical that it is a firm snug fit and should resist you well you try to spin it on your finger. But not so tight that you can not get it off or when it gets fatter from humidity or exercise. So it is hard to fit. Get these to test with. And wear them for 24 hours or more before deciding and chose a ring size that may fit multiple fingers snugly so you may be able to find one that works in different environments for you. ... show more
Reviewed in the United States on May 14, 2025 by Stacey W.
    • Good sizing and comfort tool
Style: Sizing Kit Color: Sizing Kit Size: Sizing Kit
Great sizing tool for Oura, and I think for general ring sizing too. The sizing ring is a little thinner than the ceramic version, but it’s a good tool for sizing and to make sure you choose the right finger.
Reviewed in the United States on April 1, 2026 by Brian S.
    • Easy to use
Style: Sizing Kit Color: Sizing Kit Size: Sizing Kit
Easy to use and figure out your size. Very clear instructions
Reviewed in the United States on May 14, 2026 by MD Larson

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