Question: are ring sizes in inches or cm?
Answer: Common ring sizes for women are 6 (16.5 mm), 6.5 (16.9 mm), and 7 (17.3 mm). For men, the most common sizes are 10 (19.8 mm), 10.5 (20.2 mm), and 11 (20.6 mm). The ring size chart above should tell you how many millimeters the matching circle is as well as what ring size that measurement correlates to.