I wear a size 6 across the board, but decided to order a 6.5 based off of all of the reviews saying that these ran small...the 6.5 was too long and the canvas material is super baggy around my foot. So I ordered the 6 which fits the length of my foot way better and the canvas material hugs my foot more. My socks fit fine in the 6 as well.
I think with this little bootie it is going to depend on your fit preference...
I also ordered one in charcoal and one in olive...both colors are great but I prefer the olive since the sole is not white...