So runningwarehouse.com has this amazing tool in which you go to a shoe you’re interesting, click the button “Show me how it fits!” then you put in what shoe you wear now and what size, and the tool will tell you what size you should get in the shoe you are interested in! It’s accurate too!
I wear the Merrel Road Gloves and am interested in the Mix Master 2s. I HAVE a pair of Mix Masters in 10.5 (what I wear with road gloves), but I feel like they are a bit too big. I put in the info and the tool said I was between a 10 and 10.5 and could go with the 10 if I like a tighter fit! HOLY BANANAS!