I want to buy a T-shirt from a Taiwanese site, I am from the US and am confused by their measurements.
I am a size Large in US measurement.
So which clothing size would suit me?
x-large: W 47cm/ L 76cm
3x-large(menu show 2L): W 51 cm/ L 81cm
Again thx 
Take one of your tees that fits well, lay it out flat, and measure the width and length in centimeters, then compare it to what the website shows. If needed, err on the size of buying one too large, to allow for shrinkage.
If I had to guess I’d say go for the 3x, though. US large is often 2x to 3x here. It varies by manufacturer, though.
Is it true that an XL in the US is 2XL in Taiwan? I need to ship a t-shirt to the US.
Yes, that looks about right. I am 2XL in the US and that would probably be 5XL in Taiwan (though I am having difficulties finding my size).
Hard to say. I’m a L in US and sometimes XL in Taiwan is still too small.
For Taiwan you have to go up 1 size minimum, 2 sizes to be safe.
For China go up at least 2 sizes.
Different brands also have different “sizes”.
Ok thanks.