Different regions use different ring size standards, usually there are multiple size versions such as Hong Kong version, American version, European version, etc. Many domestic ring brands are in Hong Kong, so in terms of size, most of them use the Hong Kong version. If you're buying a ring from another region, you'll need to check the ring size chart to find that version. If you are worried that you will not be able to measure it yourself, you can go to a jewelry store and ask the clerk to help you measure it.
Ring Measurement Method 2
Prepare common tools: white strips of paper (no more than centimeters wide), pens, rulers, scissors;
Wrap a white strip of paper around the finger where you want to wear the ring, pull it tight, and use a pen to draw a mark on the overlapping place;
Measure the length between two marking points with a ruler;
Multiple measurements, take the value with the most occurrences;
Compare the size chart to get the corresponding size.
How to measure the size of the ring.
There is also a method of measurement, which is a rod that specifically measures the size of the finger. The ring size stick is a size stick with a scale and a string of rings of different sizes, the way to measure is to find a ring that is most comfortable to wear, and then put the ring on the size stick, and read the ring size.