I don't know, I found my size to be pretty consistently accurate, 4-6 in women's and 5-7 in junior's and never had too many problems with fit

Except the inseam being too long

definitely a good idea to try them on
Though with European sizes it can be confusing... all the conversion charts I find say a 6 is like a 34 in EU sizes but these ones I got from anoname are 28 and fit just right...