The sizing on these are sooo very wrong. I wear a 7.5 in street shoe, 8/40 in a running shoe for a roomier fit. I measured cm as per sizing guide and ordered an 8 which would be 1 size larger than suggested. They are absolutely painful. There is zero way any sort of break in will make these useful. I honestly don’t even know if a size 10 would work. I am extremely disappointed, however it is also my fault for ordering from Somewhere I can not return. (We have no where local within 2 hrs so online for specialty items is what must happen) usually it’s alright because i have two daughters with smaller feet and they just go down to them but they don’t even fit their feet which are 1&2 sizes smaller and much narrower. Bad buy. Size up at least 2+ sizes if you don’t want to break your feet. (I know they are supposed to be tight and uncomfortable but this is absolutely torture painful, i am extremely hyper mobile so my toes bend all sorts of ways and i can not stuff them in enough to get my heel seated.) Super disappointing