I'm surprised at how small these run although some reviewers did warn! I generally wear 6 to 6.5 shoes and have a wider foot (not exteme). I ordered a 7D and it is clearly too tight across the instep and my toe reaches the top. But my heel seems to not fit all the way back. I don't have a wide heel but maybe the shoe is so narrow in the back that I can't get my heel back all the way. But as it is, the back comes up high and cuts into my achilles so that would make it worse. I'm hoping to find a Mizuno shoe that works for me as it sounds like a lot of people are fans.