I typically wear a shoe size 8.5 regular. My feet are very slightly wide..not enough to need a wide shoe however. As usual, I ordered a shoe size up in running shoes. They felt a bit tight but ok. However, when I ran, my middle toe felt pinched and started going numb/painful (typical for me when I'm not wearing the correct shoe). I exchanged them for the wides (size 9) and they are perfect! Very comfortable run, no toe numbness or pain. My knees feel great while wearing these, so I know there's good support. Overall, I'm very happy with them.