The 7cm ring is a size 30. The length of the 7cm ring is 70mm, which generally corresponds to the Chinese ring size of 30. The standard size of the finger ring is called the hand inch. The modern hand size is represented by the number, and the Eastern hand size ranges between 8 and 28. When selecting a ring according to the hand inch, it is appropriate to wear the ring slightly tight in summer, and it is appropriate to turn around but not fall off after wearing it in winter.
How to convert the ring size
There are many ways to measure your finger size, and the relatively small error is to use a special tool, that is, a ring size rod specially used to measure the hand inch. This tool is calibrated with a series of rings of different sizes. Put a suitable ring on one of the fingers to be measured, then remove the ring and put it on the ring stick. Compare the value. This ring size bar is more common in jewelry stores.