Probably a 3.75, but....
- Familiarity: I've used it several times
- Fit: Runs small
- Size Bought: 12.5
I Have had these for a couple months now and have put between 125 and 150 miles on them *walking*. I don't run, as these knees are shot, but I do get in 3 - 4 miles walking the roads a few times / week. These are probably the most comfortable pair of shoes I have ever worn - hands down. They are wide, and I have a narrow foot, but they don't slip; they stay tight and the uppers are like air. One thing to keep in mind is that they run extremely small; I am an 11.5 in most every other shoe, but I am a 12.5 in this one. Which is odd, as my Hoka ATR trail shoes are 11.5's. Anyway, no big deal, they fit, they're just a size larger than every other shoe I have.
The *really* bad is that the soles are going to wear out rather soon. They are a 3-part material, one of which, the red material in the pictures, is solid and shows little-to-no wear...the grey and material is wearing down significantly. The *really really* bad is that they cost $150! Such a shame as they could be worth that if they would just use that red material over the entire sole - there's enough cushion to offset whatever stiffness the red material would create...if any...I'm not a tech guru. Anyway, the shoe is super comfortable, it kinda looks clownish but that's ok, and the soles are just not all that durable. Weigh your needs when thinking about buying these...