I've only ever tried on the men's shoes (because we didn't get the women's version at work ). The men's seem to run relatively narrow--the only place that seemed wide to me is the heel and I have narrow-end-of-B feet and a narrow heel. One of the managers said that she thinks they run somewhere between a normal men's and a normal women's shoe, sizing-wise. I tried the Avenirs (road shoes, but I think the MTB version uses the same last), and they were very comfortable. I think if I were to get the women's version of these, they'd probably be okay.