I bought these in a M as I've heard other brand winter breeches fit small - not the case for these! I'm mostly a size 27 (vary from 26-28 depending on rise of jeans, brand etc). They're a tad big, but comfortable. Room to add a layer or two under, though, so it worked out for super cold days. These are truly beautiful and feel like $300 breeches! Very luxe, warm, beautiful fit! Once black size S is back in stock, I'll buy a pair in my usual size for a more compressive fit :) Super happy with the purchase.