Oura Ring Sizing Guide: How to Find the Perfect Fit

One of the most important things you need to get right when buying the Oura Ring is the ring size. And that’s why I have created this Oura Ring sizing guide to help you.

Since the fitness ring is meant to be worn 24/7, it is important to get a size that is comfortable and fits well. Also, to get accurate readings from your Oura Ring, it is important to make sure that it fits properly.

One of the most common methods for determining your Oura Ring size is to order a sizing kit. This kit includes a range of ring sizers in different sizes (6 – 13) that you can try on to find the best fit.

Why Ring Sizing is Important

Choosing the right size for your Oura Ring is crucial for its functionality and comfort.

A ring that is too small can cause discomfort, while a ring that is too loose can easily slip off your finger and get lost.

Additionally, an ill-fitting ring can affect the accuracy of your sleep and activity tracking.

Factors to Consider when Determining Ring Size

Changes in finger size throughout the day

Your fingers can change in size throughout the day and in response to environmental factors such as temperature and humidity.

This is why it is recommended to wear the ring sizer for at least 24 hours to confirm your best fit.

The finger you will be wearing the ring

Since different fingers are different in size, you need to take your time and think carefully about the finger you want the Oura Ring to go on. Later changing the finger will mean ordering another ring. For instance, if you order the ring for your thumb and later realize the ring might look better on the index finger, you’ll have to buy a new ring for the index finger.

NB: Oura recommends the ring be worn on the ring, index, and middle fingers, but you can still wear the ring on the thumb or pinky finger effectively.

The hand you’ll be wearing the ring on

Finger sizes on your dominant hand may differ from those on your non-dominant hand, so it’s recommended to measure both hands and choose the larger size.

How to Measure Your Ring Size for Oura Ring

Before purchasing an Oura Ring, it is crucial to measure your ring size to ensure a comfortable and accurate fit. Here are some steps to follow using the free Oura Ring sizing kit:

NB: You will find other ways of measuring your ring size online (like using a string or piece of paper), but I prefer sticking to using the free Oura Ring sizing kit.

Oura Ring Sizing Guide
  1. Place your order for Oura Ring (at this point you don’t know your ring size).
  2. The Oura Ring sizing kit is shipped to you in 3 to 9 days.
  3. Decide the hand you want to wear the ring on. Fingers on the dominant hand tend to be larger than those on the non-dominant hand.
  4. Decide the finger you want to wear the ring on. Even though the Oura Ring can be worn on any hand, Oura recommends the index finger for accurate readings – with the middle and ring fingers as the best alternatives.
  5. Use the sample rings from the kit to find your size.
  6. Wear the sample ring for 24 hours to be sure. The finger can change in size due to temperature and time of day.
  7. Once you have your size (6 – 13), confirm it by visiting the link on the sizing kit’s packaging.
  8. The Oura Ring will be shipped to you.

By following the above steps, you can measure your ring size accurately and ensure a comfortable and accurate fit for your Oura Ring.

Tips for Accurate Ring Sizing

Choosing the right size for your Oura Ring is crucial to ensure it fits comfortably and accurately tracks your data.

The following are some tips to help you determine your correct ring size for Oura Ring:

  • Use a sizing kit: Oura offers a free sizing kit to help you determine your size accurately. Make sure to follow the instructions carefully when using the kit to ensure an accurate reading.
  • Try different fingers: Take the time to try the ring sizers on different fingers. Switch sizes, switch fingers, and find the most comfortable combination for you. Oura Ring is built for any finger, so find the right balance of style and comfort to fit your needs.
  • Test the fit: Once you have determined your size, test the fit by making a fist while wearing your ring sizer. If you see a gap between the top of your finger and the inside of the ring, you might need a smaller size.
  • Wear for 24 hours: Your fingers might slightly change in size based on the time of day, so it is recommended you wear the ring sizer for at least 24 hours to confirm your best fit.

Remember, the accuracy of your Oura Ring’s data depends on how well it fits your finger. Take your time and follow these tips to ensure you get the right fit for yourself.

Common Ring Sizing Mistakes to Avoid

Choosing the right size for your Oura Ring is crucial to ensure accurate tracking and comfortable wear.

Here are some common mistakes to avoid when determining your ring size:

  • Not using the sizing kit: The free sizing kit provided by Oura Ring is the most accurate way to determine your ring size. Skipping this step can result in an ill-fitting ring.
  • Assuming you know your ring size: Even if you know your standard US ring size, Oura Ring measurements may differ slightly. It is recommended to use the Oura Ring sizing kit to ensure the best fit.
  • Choosing the wrong finger: Make sure to measure the finger you plan to wear the ring on. Different fingers have different thicknesses.
  • Not considering ring orientation: The Oura Ring is designed to be worn with the sensors facing the palm of your hand. Make sure to orient the sizer correctly when testing for fit.
  • Not testing for snugness: The ring should fit snugly on your finger without being too tight. Make sure to test the snugness by shaking your hand and ensuring the ring stays in place.

Oura Ring Size Chart (in Inches)

Oura Ring SizeSide-to-Side DiameterTop-to-Bump Diameter
Size 60.67”0.60”
Size 70.70”0.63”
Size 80.73”0.66”
Size 90.76”0.70”
Size 100.79”0.73”
Size 110.82”0.76”
Size 120.85”0.79”
Size 130.89”0.82”


Can I determine Oura ring size without a sizing kit?

Yes, it is possible to determine your Oura ring size without a sizing kit, but it is not recommended. It is generally recommended to use the Oura ring sizing kit to determine the correct ring size for you, as the ring sizes are slightly different than standard US ring sizes.

What sizes does Oura Ring Come in?

The Oura Ring comes in 8 different sizes (6 – 13). The ring sizes are slightly different than standard US ring sizes. The rings weigh between 4 to 6 grams (0.1-0.2 oz.) depending on the size.

What if I am between sizes?

If you are between sizes when choosing an Oura Ring, it is generally recommended to size down than up. The ring should fit snugly on your finger, but still, be comfortable to wear. Sizing up may result in a loose ring that will keep rotating or slipping off.

Can the ring be resized after purchase?

Unfortunately, the Oura Ring cannot be resized after purchase. The rings come in eight different sizes and there is a free sizing kit so that you are sure about your ring size before making a purchase.

Oura ring too loose: What do I do?

If your Oura ring is too loose and does not fit properly, you can return the fully functional and undamaged Oura Ring within 30 days of receipt for a refund or exchange for a different size or color within the same price range.
NB: After one exchange has already been completed, you will not be able to make further changes to the size, style, or color.

What is Oura Ring’s smallest size?

The smallest size available for the Oura Ring is size 6 (0.67”). The Oura Ring sizing kit includes eight plastic ring sizers, ranging from size 6 to size 13.

Is there an Oura Ring size 5?

There is no Oura Ring size 5. However, the Oura Ring Gen3 is available in different sizes, including sizes 6, 7, 8, 9, 10, 11, 12 and 13.


Ensuring that your Oura Ring fits properly is essential to getting the most accurate readings from this cutting-edge wearable technology.

By following Oura Ring sizing tips and steps in this post, you’ll be on your way to finding the perfect fit for your ring.