I work in a pharmacy and am on my feet 8 to 10 hours a day. These are the best shoes that I've owned for foot comfort. As others have found, they do run large. I normally wear a size 9-1/2 D in a regular oxford shoe and a size 10 M in a New Balance athletic shoe. This shoe fits me best in a size 9 M. I did buy another pair of these Clark's in another color in a 9-1/2 M and the fit seems a bit large. They still fit good enough to continue wearing and did not affect the comfort, but I prefer the smaller size. I was wearing the Dockers Gordon shoes and they were not too bad, but at the end of the day I did have some foot discomfort. The Clark's were great right out of the box and are significantly better.