I sized up, as suggested by a friend, and am very happy with the fit. I went for the size XL and I am normally a US size 10 (AU size 14). This style (the Classic) provides nice full-bum, high-waisted coverage, and gives me the secure feeling I have been craving from period pants. I am especially appreciative of the additional front coverage. Front-bleeding is a thing! No other brand seems to cater to this and I constantly leak out the front of the gusset (and sides) in other brands — and finally these do cater to this and there have been ZERO leaks — hooray! I have now gone and ordered a bunch more and can do away with my old period pants from other more-expensive, well-known brands. The cotton fabric is really nice and soft too. I'm a total convert. Thank you, Fri Period, for creating these.