Ok, it looks like a science thing-- but my measuring tape has a 1cm metal tab on the end, plus it has my name written in marker over the centimeter side because in the US, who sews with centimeters? Now of course, I need to go get a narrow cm measuring tape so I can sew for dolls.
Anyway, I figured a picture would be better so that people could see where I was measuring. I would still take these numbers with a grain of salt, and use a muslin to create your pattern first. The tape draped over his shoulder starts noplace--it was just so that if someone wanted scale, there would be something there. The 15 cm mark is exactly on his shoulder seam, though. His wrists are around 7cm, the mobility joint line is about 18.5 cm around.