I ordered these boots because I wanted the Donald Pliner's like them but did not want to pay that price.  My calf is a little over a 15 and it was a tight squeeze getting the zippers up.  I was able to with leggings on but I know that I will not be able to wear these with jeans tucked in.  The boot is a true to fit for me.  I wear an 8.5M.  I will not be able to wear these with thick socks though ( I am in TX so it shouldn't matter there).  I have only walked around my house in these and they are comfy but may need a little breaking in to wear all day.  They are beautiful and very nice looking.  Kinda dressy.  They make my legs look slim because the boot is very narrow.  There is no extra room in the ankle like some tall boots.  Nice slim line up to the knee.  Very nice boot.  I am in the process of losing weight so it won't be long and they will be easier to zip.  All in all I am happy with my purchase.