Cant help you with Rogans (I just took the plunge myself on Bluefly, which is what I think you're looking at). I think it might depend on what you consider a "perfect fit" in terms of PDC. In my case, I'm generally a 32 and can fit into a 31 in PDC, but generally it's a very very close fit that can be uncomfortable when sitting or moving. A 32 in PDC is slightly baggy on me, but still within the realms of a good fit, and is much more comfortable; I prefer some room in my jeans. That said, I got a 32 in Rogan, and I'd recommend you get a 34. I'm pretty sure Rogan does odd sizes like 33, 35 too, so I honestly don't see how a 36 would fit unless they cut on the extreme small side. If it doesn't fit, returning the jeans to the vendor shouldn't be too much of a hassle.