Narrowest and thinnest guys have not bred out yet. The mules fit normal on me (narrowest thinnest also). According to online google search formula : im a 9.25 ,so tried a 9 and almost fit but too much forcing , if I was .25 shorter in stature height , 9 would be perfect. Or if wore thin liner socks only. Also noticed my toe exceeded the red arch.
Tried the 10 and still had to fahnagle foot in, but has some play. Noticed my toe stopped before the red arch.
So im a 9.25 (google search) needing a 9.5 ( add some room) and am narrow and thin.
The mules seem to be a narrow (title is missing that, unless mule implies the opposite) size, however the size number is true. Round up even if its 7/8 inch, buy proper insert if needed.
Only downside is material of sole , this material wears almost fastest compared to others. Supposedly thick polyurethane lasts almost longest. I still bought a pair, thinking of buying another. Great for low calorie burning activities, like grocery shopping and other casual events, maybe for house shoes too (may be considered a premier house shoe). Wouldnt wear them for high burning like exercise or employment or any type of manual labor.