Wow! That is a difficult question. I would think that they are a true 10 and there would be a few inches of space in the back if a person who wears a 9 1/2 had them on. I wouldn't think that it would be unsightly or an excessive amount of additional room though. After all, there isn't a full size difference between a 9 1/2 and a 10. Thanks for your interest. I hope that I was able to answer your question. :) I hope you will place a bid.