I went to the Dickie's website for sizing instructions, and took measurements as directed. My bf measured 41" where the pants sit, so the recommended size to order was 40 or 42. Now, since he already owns two pairs in size 36 that fit a little on the tight side on the waist since he gained a bit of weight, I decided to order a 38, a size up. The 38 fits a bit looser on him, there is quite a bit of stretch room and he needs a belt to keep them from slipping. Overall, besides the sizes running large, these pants are durable. My man works hard and has put his pants through a lot; knees, pockets, bending, everything. Over the past year of owning two pairs, the wear has shown: - In the pockets. There are some holes. - Buttons. Both buttons busted after about 6 months of wear. Both times, the plastic in the center broke free from all four button holes, with it stuck in the center after the button came off. They're sewn in, so the remaining material was easy to remove, and it was easy to repair. - Bottom leg holes, near the heel. My man has short legs, and I don't think they make anything shorter than the 30's. Because of this, I am giving a bit of leeway. - Overall fabric thickness. It is to be expected that any fabric wears and thins overtime. It has thinned quite a bit overall, but it is still holding together. Another thing to note is that there are TWO versions of the "Dickies relaxed straight fit cargo pant". One is a flex version, the other is not. The markings were not clear to me when I went to buy him more pants, and I accidentally bought him the wrong version: the non-flex ones. The non-flex version runs about a size smaller than the flex version. The non-flex ones have a hook-and-eye type closure, lack the cell phone pocket, feel stiffer, and have a more straight/less legroom style cut. They do not stretch. These here on this page are the flex versions: which have a button closure, cell phone pocket, more of a fabric-type feel, and run about a size larger than their non-flex counterpart. They also stretch and move with you.