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.
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.