Said it all in the description. I wear a size 13 street shoes, the size 14UK which is size 15 U.S was wicked tight on my left foot, but if I had normal Roman-style feet, it would have fit better. If you have normal width or slightly wider than normal this is a good shoe, but if you have big feet or a super-wide foot, it's difficult. What I loved most, was the slipper feel to the inside, & rubber was good. But I ended up buying the Scarpa Instinct VS, & they are the best shoes I've ever owned for climbing. Highly recommend the 3force system if u have tiny feet from OCUN, but if you have wicked wide feet nothing beats the Scarpa Instinct. They don't look as nice or cool, but they stay locked on the foot and heal. If I wore a size 12U.S and I would Go with Evolv Kronos, But they don't make a size big enough for me in that version. This is indoor climbing only that I do.