I bought another pair of these in the store in an XL.  They fit perfectly, so i ordered a XL when i bought these.  They are to big.  I have to pin them to keep them up.  I am not sure why there is such a big difference.  They are long and I am very tall so i was happy with the length.  If you are short, you will need to hem them, if you are tall you will be happy.  I would order a size smaller then you usually take for this item.