It will depend on the brand you pick to try on. Torrid brand always seemed to be a little bigger then the designer jeans. The designer jeans fit a bit snug on me. And the length is average. Maurices and Lane Bryant have more lengths. I am tall and have developed a more womanly figure in my 20s and I have found that Lane Bryant jeans fit my body type better. I am willing to pay the extra $$$ for an amazing fit.
I have shopped at Maurices and Lane Bryant. I find that Torrid has a larger variety of clothing and a more appropriate sizing chart. Maurices' plus size section I have found lacks true plus sizes, and Lane Bryant seems to have a higher price tag than Torrid. I may be mistaken.