“If you have high arches like I do order the next size larger. As in if you are a size 10 us order the size 11 us. They do not have a size 10.5. I have found that may left foot arch is higher than my right foot. After receiving the size 11 the left foot was still a little snug but definitely doable. I am a great fan of this company and have many pairs if there product. Sincerely, Jim Lawson”