I was sized at REI as an 8 and told that the Merrells are wider in the foot but narrower in the heel, which was true for my feet. I wore the shoes around the house and ended up exchanging them for a half size larger because my crooked toes felt cramped. The extra length also fit the bunion on my L foot better. My feet, knees and hips did not hurt at all at night after walking all day in these shoes which made our Yellowstone trip even more enjoyable. My husband also got a pair of Moab Merrells in a 1 1/2 larger size than he normally wears but they too were very comfortable on the hikes.