I normally wear a size 10/10.5ish, and a pair of 9s in ash were just a bit too small. Ordered a pair of 9.5s, and so far they have lasted me about 5 months with moderate to heavy wear, and they even held up in the washing machine! I just ordered another pair of 9.5s in red, and they are definitely larger than the 9.5 in gray, but not so big that I feel the need to return them. Be prepared to exchange size if necessary!