The circumference of the US size 9 ring is 59.5mm and the diameter is 18.9mm, which is equivalent to the size 18 ring in Chinese ring sizes and the size 59 ring in European ring sizes.
What to pay attention to when measuring ring size
1. It is recommended to choose a thin rope or paper without elasticity for measuring PROPS, and not to use cotton thread or rubber bands.
2. When reading values, the line of sight should be parallel to the scale being read to avoid errors caused by different angles, preferably accurate to 0.1mm.
3. Due to the easy thermal expansion and contraction of finger blood vessels, there may be deviations in measurements at different temperatures and seasons. Measurements may be tighter in summer and looser in winter. It is recommended to take the average of multiple measurements at different times.
4. There are different versions of the ring size comparison table, such as international version, mainland version, Hong Kong version, etc. Different versions correspond to different ring sizes. When purchasing, it is important to be clear which version of the ring size chart the brand is using.