I wear size 10 regular width, sometimes 9.5 in boots (since they all seem to run large...on purpose ). Reviewers mentioned that this boot runs narrow, so I bought a 9.5 Wide. They are right! The wide size was just barely comfortable.  Yet the shoe  was too long, I can't imagine how enormous the size 10 would've been.

The calf is also too wide and looked like I was wearing  buckets. My calf is 14.5" at the largest part.