I have been looking for grey boots like these for a looooong time, so I took a chance based off of some reviews here and because other sites listed the circumference as 17". The first time I put them on I thought there is no way I'll get these zipped. I gave it another try and was able to squeeze that zipper up! I wear a 9.5, sometimes 10. I ordered a 10M and they are really closer to a 9.5 than a 10. They are comfy overall but are tight across the top of my foot/instep. I don't understand why this boot isn't offered in a wide width---If these were wide width, they would be perfect. I got these on sale for $45 and considering they are good quality leather/suede and nice looking, I am keeping them. I have muscular, 17.5" calves and if you have wide calves, I wouldn't consider these unless you wear a larger size for wider circumference.