I have a 15 lb cocker spaniel that I would call a small to medium sized dog. I have a basset that I would call a large dog. He's 45 lbs, but can get to stuff that a 100 lb mastiff could get to. He's short, but in terms of size and bulk, he's a large dog IMO.Whereas I consider Webster "small" at 23lbs, 17.5" and Kim "normal/upper end of medium" at 53lbs, 23". They represent about as small a dog as well as close to the upper size limit that I would seek. So my sister's 8lb dog is, to me, an "itty bitty" size...whatever that translates to in miniature/toy/etc. terms. Cute, but itty-bitty, lol.
Then again I also consider basset hounds to be Large dogs, though they fly in the face of the height many people seem to require to consider a dog large.