If you have a ring that fits you well, you can use it to measure your size. Find a printable ring size chart online that you can use at home.

Use this number while looking at a ring size chart to determine your size. Most sizing charts are in millimeters, so it’s best to stick with that unit, especially for international ring sizes.

The Oura Ring 3’s sizing kit includes eight plastic rings ranging from size 6 (the smallest) to size 13 (the largest). Based on our measurements of the Ring 3, these sizes are basically the same ...

Oura launched a new version of its iconic ring in fall of 2024, promising better accuracy and a more comfortable design. That’s the fourth-generation Oura ring, which I’ll be calling “gen 4 ...