Merrell shoes usually run small. If you normally wear a 10 U.S. it is recommended to buy the 11, otherwise your toes will touch the front of the shoe. Not sure if a 10.5 would be big enough either. My husband normally takes a 13 shoe size and had to go up to a 14 in the Merrell's. Myself, I take a 6 to 6 1/25 and to buy decent hiking shoes/boots, I had to go up to a 7 1/2 in womens.
