These run big so they can go over clothing such as blue jeans or whatever.  THe same is true for the jacket. This material is more flexible and thinner than most slicker bibs and jackets. I haven't worn it in the weather yet- but after last weekend outdoors for 2 days in a flood, I decided to buy now- better to have and not need and all that.
Anyway, I usually wear XXL in HH jackets and such, but the XL is the right size for me in the Impertech Jacket and pants. THe XXL will go over a winter coat, which is not why I'm buying this.  I tried a Large (I'm thick 6/3), and it was form fitting, again, not what I'm looking for, so I will return and get the XL.  THe XL, on paper, looks to be too long, but I'll give it a shot. The L size was the right length but no room in the seat/crotch/bib portion.