Sizing: The Perfect Ring
The chart below shows U.S. ring sizes and their corresponding diameters in millimeters. To find your size, use a ruler to measure the inside diameter of a ring that fits your finger perfectly. This chart is useful if you or the recipient has a ring that can be measured this way. It’s important to ensure the ring will be worn on the same finger for which you're measuring.
Multiply the diameter measured with 10 to convert cm into mm and use the chart below to find out your ring size. (Eg: 1.73cm x 10 = 17.3mm) 17.3mm = U.S 7