Upload & Sell: Off
YES! I guess your´re right; theSuede. Digital files are pixels by pixels without any particular number of dpi correspondence. DPI´s (dots per inch) are simply not their unit for dimensions, but pixels. Makes sense. It´s correct.
Using "your formula" and making a fast comparison:
Sigma can give me a 4704 x 3136 pixels / 300 dpi =17,1"x10,4" inches (43,4 x 26,4 cm). Almost a DIN A3 paper format.
Canon 5DMII (my current camera) give me 5616 x 3744 pixels / 300 dpi = 18,7" x 12,4" inches (47,5 x 31,6 cm)
Sigma is alright for most of my needs in terms of offset prints. Heavy Canon for studio/macro. Light Sigma for travel.