A properly fitting Oura Ring will ensure the highest possible data accuracy, comfort, and overall experience. Whether you’re new to Oura or switching in between Oura Ring generations, here are some tips to help find your ideal Oura Ring size.

Sizing Kits
Oura Ring Generations
Find Your Ideal Fit
After You've Chosen Your Size
Between Sizes?
How to Check Your Oura Ring Size
If Your Oura Ring Doesn't Fit

Check out our Oura Ring 4 sizing video:

Sizing Kits

We don't sell individual sizing kits through the Oura online store. If you choose the Size Later option, a complimentary sizing kit is included as part of your Oura Ring purchase. 

However, many authorized retailers sell sizing kits separately. When you purchase one, you'll receive a credit towards a future Oura Ring purchase from that retailer.

If you've already used a sizing kit or received one from a friend or family member, you can select your size directly at checkout.

Oura Ring Generations

The sizing for each Oura Ring model differs slightly between generations. Make sure to use the right sizing kit for the most accurate fit. The sizing kit boxes are labeled with the generation number that they are intended for.

• Oura Ring 5 Sizing Kit: white ring sizers, sizes 6–13
• Oura Ring 4 Sizing Kit: white ring sizers, sizes 4–15

Find Your Ideal Fit

Our plastic sizers are designed to guide your size selection, but they don’t reflect the quality, feel, or weight of the final Oura Ring.

1. Open Your Sizing Kit

Inside your sizing kit, you’ll find multiple plastic ring sizers). Oura uses only whole sizes (no half sizes) and they differ slightly from standard US ring sizes, so it’s important to test with our sizers even if you "know"” your usual ring size. Avoid sizing your Oura Ring based on other rings, as they likely use different measurements.

Oura Ring and ring sizers are the same width and circumference. However, the Oura Ring itself weighs slightly more due to material differences.

2. Choose Your Finger

You can wear your Oura Ring on any finger, but for the best accuracy, we recommend your index finger. The middle or ring finger also works well, just try to avoid fingers where the knuckle is much wider than the base.

Try the sizers on both hands and different fingers to find the most comfortable fit. If your finger size ever changes, you can move the ring to another finger or hand as long as it fits snugly.

3. Check Ring Orientation

Oura Ring 4 Wear the ring sizer with the size number visible on the top of the hand.

Oura Ring Gen3: The sensor bumps inside the ring sizer should be on the pad (palm side) of your finger.

4. Test for Comfort

Your Oura Ring should feel snug, not tight. It should stay securely at the base of your finger and come off with a bit of soap and water, but not slide off easily.

Make a fist: If you see a gap between the ring and the top of your finger, try a smaller size.

5. Wear it for at Least 24 Hours

Fingers change size throughout the day and night. Wear the sizer for a full day, including while you sleep, to make sure it still feels right during different activities.

After You've Chosen Your Size

Once you’ve found your ideal fit, you’ll need to confirm your size before your ring can be shipped.

• If you purchased your ring from the Oura online store, confirm your size through My Orders
• If you bought your sizing kit from an authorized retailer, return to the retailer and purchase your ring size
• If you received your ring through a specific employer program, confirm your size through business.ouraring.com
• If you received your ring through Essence Healthcare, scan the QR code on the back of your sizing kit or see this Essence Healthcare article

You don’t need to return the sizing kit. Feel free to pass it along to someone else who might be interested in Oura or recycle it.

See more information in How to Confirm Your Oura Ring Size.

Stuck Between Sizes?

We recommend choosing the smaller size for a few reasons:

• The sensors inside your Oura Ring work best when they stay in close contact with your skin, especially the underside of your finger
• A snug fit helps keep your data accurate and your experience consistent
• Our plastic sizers can feel a bit "stickier" on your skin, so the actual Oura Ring may fit more smoothly

How to Check Your Oura Ring Size

If you already have a ring, you can find your ring size either inside the ring itself or in the Oura App. The size is marked on the inner side of the ring, opposite the sensors. To check in the Oura App, tap the icon in the upper-right corner of the Today tab to go to the My Devices page, and tap on your ring. 

If Your Oura Ring Doesn't Fit

If your Oura Ring feels too tight or too loose, even after using the sizer, reach out to our Member Care Team and we’ll work with you to find the right size or solution.

You can contact us here.