Keen Men's Arroyo II and Women's Arroyo II run 1/2-1 full size large. Women's Arroyo II Hiker sizing is correct. Odd since they are the same platform. I also found a manufacturing defect in one shoe, very bulgy toes. Otherwise, same Keen quality. Re-ordering down 1/2 size for both of us and taking it from there. The Arroyo II Hiker works great for cycling, just no SPD clip in ability. If you're not spinning or racing it's still a fine and stable grippy cycler/walker. Looks as good on the Domane as on the FX.