In measuring this , it appears to be 11” with nearly a 1/4” + if you are taking it from the edge of the shoe (see pics) it’s more of a 13 ? You do the math . The width is just over 3” as well there is some give to the shoe too so it can accommodate many foot shapes This so-called 280mm is a 12.5-13 because the shoe isn’t closed and narrow … very much realm of 12-13 very nicely . The peep toe is of course part of the way they accommodate as well as the width and loft. So much fun . I’m sorry I had to put these up , now you’ve got a dilemma 🤣🤷🏼