I normally wear a 9.5-10 in US shoe sizes. I purchased the 41 and they fit perfectly.

These are probably the coziest Lolita shoes I've worn! I ordered a size 36 -- I'm a 6.5 or 7 in US sizes, so I worried it was too small, but they fit like a glove. The soles are much comfier than most shoes, I don't even have to wear my inserts with them.