Tea Party sizing

[rainbowsquash.livejournal.com]

I'm looking to purchase some An*Tai*Na tea party replicas from Taobao and I was wondering what size would fit me best as I've heard conflicting information about sizing (I've read in one place that they run small and another that they run big). My foot measures exactly 25cm and I purchased a size 40 previously but they were painfully small on me length-wise. I'm not sure whether I should go up to a size 41 or a size 42 this time as I am not knowledgeable about Chinese shoe sizes. Any help would be really appreciated ♥