Did you know that the labeling systems for knitting needle sizes are different in different areas? If you are like me, who look up patterns from many different places (US, Europe, Japan, Taiwan, etc…) then you will find this link useful:
However, I think that the above link is more geared towards UK and US knitters, because in reality, Japanese knitting needles are sized in 0.3 mm increments (!!!), as compared to US or UK needles, that are sized based on the metric system, i.e. increment by half or quarter of an mm. See this link below that shows a complete list of Japanese knitting needle sizes:
In other words, it will be difficult for me to always match the needle sizes to the Japanese patterns that I use. For this reason, it is important to do what’s called gauging, which basically involves knitting a swatch and then adjusting the number of stitches of your pattern based on the size of the swatch. But that is topic deserves its own discussion, so I will save it for later.