I first went to try these shoes on in a shoe store so I would know exactly what size I took and what felt most comfortable since I will be running in them. Normally I wear a 7.5-8 in women's shoes, but I usually wear an 8-8.5 in running shoes. I tried on an 8 in the store and I thought they fit good at the time to the point where I didn't think twice about trying on a half size up. So I went home and ordered the shoes online instead of buying them in store because they're always more expensive in store. I eventually received the size 8 I ordered and they surprisingly were too small, unlike the ones I tried on in store. So I returned them and ordered an 8.5 and they fit me perfectly. I know everyone's feet are different but I would recommend sizing up a half size, keeping in mind that whatever socks you wear with them will help determine the fit.