sofa because of style and styles varied , it is difficult to have an absolute size standard, only some conventional general size. Arm of the sofa as tall as 560-600mm single formula : Length : 800-950mm, depth : 850-900mm; Seat height : 350-420mm; back High : 700-900mm double formula : Length : 1260-1500mm; Depth : 800-900mm three formula : length : 1750-1960mm; depth : 800-900mm four formula : length : 2320-2520mm; depth 800-900mm