They run small for American sizing (I know 2XU is Australian). Most brands I'm normally a large or maybe a medium. I had to order an XL which fits me perfectly. I expect this from known European brands. Was surprised by 2XU small sizing. I absolutely love this product. The pad is a little wider than several other brands, just enough to properly cover my sitz bone area when I'm in full aero. Worn them for 5 rides so far, 2 of which are over 100 miles and they are super comfortable. The leg band provides grip but doesn't cause the sausage effect.