Oura Ring Sizing (Tips for Determining Your Size)

Oskar Fällman

Updated on:

Oura Ring Sizing Kit

It’s important to choose the correct size for your Oura ring for it to function properly. When ordering the ring your will get a ring sizing kit including plastic models in the sizes US6-US13. Follow the step-by-step guide for using the kit and keep in mind the tips below while trying on rings to determine your Oura ring size.

In short, the first thing to decide is what finger to use, you can wear the Oura ring on any finger, the pinky, ring, middle, index or even the thumb. It’s recommended to wear the ring on your non-dominant hand to reduce the wear of the ring, wearing it on the dominant hand will make it be in the way when doing specific tasks.  

For the best performance and accuracy wear the ring on the index finger. The middle is also a good alternative in case you’d prefer another finger, the key is to have the sensor firmly touching the skin of your finger and creating good contact. That’s why you should avoid fingers where the base is narrower than the knuckle. 

Note: The author wears his Oura Gen 2 on his non-dominant (left hand) index finger.

The Oura rings are not the same size as regular rings so you cannot use a normal size kit. The ring sizes are slightly different than standard US ring sizes and there are currently no half sizes. It is recommended to use the Oura ring sizing kit to determine the correct ring size for you. Down below is a guide with Tips and Trix on how to choose your size both with and without a kit. 

How to Choose Your Size When You Got the Sizing Kit

Once you’ve received your sizing kit and found your perfect fit. The difference between the ring sizers and the Oura ring will be the material and therefore the Oura Ring itself weighs slightly more. The size,  width and circumference are the same. 

It is important to have a proper fit of the ring and good contact between the sensor and the skin, to not only ensure a result with high data accuracy but also good comfort during the whole day. The Oura ring is meant to be used 24/7. 

It’s a good idea if possible to choose a size that allows you to move your ring between fingers and/or hands. Your fingers change size depending on the time of the day or other outside factors.

Oura Ring Sizing Kit US6-US13
Oura Ring Sizing Kit US6-US13
  1. Choose The Finger To Wear The Ring
    The first thing is to decide on the finger to wear the Oura Ring on. The Oura Ring works on all fingers and can be worn on either hand. For optimal performance and accuracy, it’s recommended to wear your Oura Ring on your index fingers and for comfort on your non-dominant hand.
    Note: If you prefer another finger, the middle or ring fingers are the next best.
  1. Comfortable and Snug Fit
    It’s important that the Oura Ring fit tightly and securely around your finger, but not to the point where it’s uncomfortable.  The sensor bumps shall be on the inside, palm side, to ensure accurate data recording.
    Note: If you see a gap between your finger and the inside of the ring, you might need a smaller size.
  1. Wear it  for at least 24 Hours
    The Oura Ring is designed to be used 24/7 every day of the week. Your fingers will expand and contract during the day. The fingers may be slightly larger in the morning compared to the night and other environmental factors can also change the fit of your ring. That’s why it’s recommended to wear the ring sizer for at least 24 hours to ensure a comfortable fit throughout the day.
    Note: The ring shall not rotate when doing normal daily activities.

If You Are Stuck Between Sizes

If you’re stuck between sizes it is recommended to choose the smaller of the two as long as both are comfortable to wear during the day. This is because of two reasons, accuracy and fit. 

A tighter ring will help the sensor to always remain in contact with your skin. A good contact will create a better signal between the LED light and sensors inside the ring and the arteries in your finger. This will help with the accuracy of the measurements and large gaps will make the ring useless. The sensor bumps inside your ring should be on the palm side of your finger.

The real version of the Oura ring is made of another material than the plastic used in the Oura ring sizing kit. The plastic is a bit stickier on your skin and therefore won’t slide off as easily as the final product. It is recommended to size down if you are having problems with your test ring staying in place.

3D Print the Sizing Kit

There is also the possibility of 3D Print the sizing kit if you have access to a 3D Printer. There are some things to consider and it’s recommended to order the sizing kit as there could be some slight difference in the print compared to the real ring. If you plan to 3D at least choose high-quality material and measure the dimensions afterwards and compare it to the sizing table in this article to ensure a good fit.

Oura Ring 3D Print Sizing Kit
Oura Ring 3D Print Sizing Kit STL File

The files can be downloaded from the official site, Oura Ring 3D Printing files, each ring is its own file.

Oura Ring Gen 2 Size Information

The Oura Ring Generation 2 size measurements are meant as a guide and reference if you don’t have access to the sizing kit or are 3D printing your rings. There could be a slight variance between the measured value and the final ring because of material variance and measurement equipment. We recommend you get the kit if possible to ensure a good fit.

There are two measurements of importance, The largest diameter of the ring (side-to-side) and also the smallest ( top to the sensor bump). The smallest is important when deciding your size as the ring needs to be able to pass your knuckles. 

The sizing kit and ring are almost true to size, there can be some variance between the kit and the final product.

The ring thickness and height are about the same for all the rings, regardless of size.

oura ring diameter measurement
Oura Ring Diameter Measurement Guide

Ring thickness: ~2.9 mm
Ring height: ~7.9 mm

Size (US)Diameter (Side-to-Side)Diameter (Top-to-Bump)
616.8 mm15.2 mm
717.6 mm16.0 mm
818.4 mm16.8 mm
919.3 mm17.6 mm
1020.0 mm18.4 mm
1120.8 mm19.2 mm
1221.6 mm20.0 mm
1322.6 mm20.8 mm
Oura Ring Gen 2 Sizing Chart

Oura Ring Gen 3 Size Information

The Oura Ring Generation 3 size measurements are meant as a guide and reference if you don’t have access to the sizing kit or are 3D printing your rings. There could be a slight variance between the measured value and the final ring because of material variance and measurement equipment. We recommend you get the kit if possible to ensure a good fit.

There are two measurements of importance, The largest diameter of the ring (side-to-side) and also the smallest ( top to the sensor bump). The smallest is important when deciding your size as the ring needs to be able to pass your knuckles. 

The ring thickness and height are about the same for all the rings, regardless of size.

oura ring diameter measurement
Oura Ring Diameter Measurement Guide

Ring thickness: ~2.9 mm
Ring height: ~7.9 mm

Size (US)Diameter (Side-to-Side)Diameter (Top-to-Bump)
616.9 mm15.2 mm
717.7 mm16.0 mm
818.5 mm16.8 mm
919.3 mm17.7 mm
1020.1 mm18.5 mm
1120.9 mm19.3 mm
1221.7 mm20.0 mm
1322.6 mm20.9 mm
Oura Ring Gen 3 Sizing Chart

The sizing kit and ring are almost true to size, there can be some variance between the kit and the final product.

FAQ Oura Ring Sizing and Tips

Is Oura Ring 2 and 3 the same size?

The rings in the Gen2 and Gen3 sizing kits are almost exactly the same size.

Which finger is most accurate for Oura ring?

The best finger to use for performance and accurate readings from the Oura ring is the index finger. The middle is also a good alternative you’d prefer another finger, the key is to have the sensor firmly touching the skin of your finger and creating good contact. 

How do I know if my Oura Ring is too tight?

Your Oura ring is too tight if it won’t come off without twisting or applying lubrication like soap/lotion. It’s also important that it can slightly move when it’s sitting on the base of your finger. If the Oura ring is too small then you can return it within 30 days of the original order for a full refund or exchange. Currently, Oura doesn’t have any sort of programs in place for re-sizing if the 30-days have passed. The best option is to try the ring on another finger and if that doesn’t work, sell it and buy a new one.

What if Oura Ring is too big?

If the Oura ring is too big then you can return it within 30 days of the original order for a full refund or exchange. Currently, Oura doesn’t have any sort of programs in place for re-sizing if the 30-days have passed. The best option is to try the ring on another finger and if that doesn’t work, sell it and buy a new one.

How to remove a stuck ring?

As with any ring, there is a risk that your finger swallows and the ring might be too tight and stuck. If it won’t come off try applying soap/lotion. Else try and reduce the swelling by fully submerging your finger in a cup of ice water, don’t worry the Oura ring is waterproof

Another common trick to remove the ring is to tightly and evenly wrap dental floss around the finger above the ring and past the lower knuckle. This will push the swelling down freeing the ring from the finger.

What to do with your old sizing kit

When you have determined your ring size then you can keep the sizing kit. Oura recommends you pass it along to some friends, in an effort for you to market the product. Another option is selling it on sites like eBay, there are users who have got $5-$10 for their kits.

Otherwise, you can recycle your sizing kit as plastic when throwing it in the trash.

About Oskar Fällman

Oskar Fällman, founder of FallmanTech, is a seasoned Onewheel rider and a visionary system engineer with a master's in Industrial Management and Engineering from Lunds University. With thousands of miles under his belt, Oskar combines technical expertise with a passion for technology and innovation. As a leader in the Onewheel community, he not only rides Onewheel's but also prioritizes safety, new innovations and the growth of the sport. As a system engineer he also holds a multiple patents and innovations. LinkedIn, Academia profile, Contact, Twitter, Patents.