I always order Merrell shoes, boots, and sandals a  half size larger. I wear a size 8, and I ordered an 8.5 for these hiking boots. These are great hiking boots! There is no breaking in required. I have hiked in them on five hikes--each hike has been 5-6 miles, up and down steep hills and over rocks. These boots are incredibly comfortable. I am just wearing regular socks (socks I purchased at Costco), nothing fancy. I love these boots!