Not got a tool and urgently need your ring size? You can try a printable ring size chart, like this one from Oliver Bonas – Greener advises that these methods can be tricky to do accurately ...

Take note of the measurement in millimeters, then compare this number to a size chart from Best Brilliance to confirm your ring size. The width of the band plays a role in how snug or loose a ring ...

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.

You can find the approximate internal dimensions of each Ring 3 size below. The above table should be used as a guide, and we don’t recommend using the dimension chart to pick an Oura Ring size.