Buy small. I usually wear a size 12 in menswear, ordered 11.5 for a comfortable fit and got soft clown shoes. It's overkill but the reordered pair of 10.5 fit my size 12' perfectly and they couldn't be more comfortable.
Men's Merrell Jungle Waterproof Slip-On Loafers in Gunsmoke - Shoes for Superior Comfort and Style
47 Review
DANSKO Wayne Black Size 11.5-12 Regular
51 Review
Ultimate Comfort and Style: Minnetonka Men's Sole Moccasin Taupe
46 Review
Merrell Men's World Vue Black Loafers & Slip-Ons
48 Review