These slippers are very cozy (I love the fleece).  I bought them one size larger because I have had trouble in the past with slippers (not from Amazon) whose toe box was too small or slipper was too constricting.  And at nighttime, or end of the day, when you are mostly wearing slippers, my feet are probably a little more swollen then they were in the morning time.  As it turns out, I probably could have done well with my "regular" size.  So I would say these slippers are pretty accurate in their sizing. Since they were a little large, I wear socks too, and that helps.  But socks help for another reason, because these slippers are so warm and they retain the heat, which makes my feet often sweat.  I am just being candid here because if you have the kind of feet that never seem to get cold, you WON'T want these.  However, if you are like me and your feet often chill, then BUY THESE.  Either way, this product is well-made and nice looking.