This is my second pair of these slippers -- the first required little "breaking in" to tamp down the copious loft of the sheepskin lining in order to fit properly. This pair is so densely fluffy that I wear them a few hours a day to squash them but still pad the house more comfortably in my older pair -- even though (after 10 years) those are falling apart. So, I know they wear well but don't appreciate that they are not a comfy fit right out of the box. I note that others have given up on their proper size ever fitting and traded up; while some note that they can become looser with wear. I'm hanging in for the latter. I wear a 10 1/2 and ordered the 11 -- they remain very snug despite a couple weeks of trying to get them to fit. It seems too far off to go a size larger but that may be necessary if you wear a whole size. I'd recommend a 12 if you're a size 11, etc. But these are very well-made slippers. (The rubber bottom is to prevent slipping around the house and on stairs -- NOT for wearing outdoors as it does not cover the entire sole of the shoe. Get yourself some moccasins or boat shoes to keep by the door for popping outside. I don't know why folks would want to wear their slippers outdoors anyway -- the point is to have a pair of clean, indoor shoes without tracking in debris and dirt from outside. ) Well, that's just my opinion. I can't recall if it was these slippers or another brand years ago for which I ordered a replacement liner when that wore down too much. I work from home so I spend a LOT of time in my slippers. Despite the fact that I'm almost always cold, these slippers keep me toasty warm and sometimes too warm. If your feet run hot, you might not want a sheepskin lined product.