I just don't get it. What are the calculations? What do you fill in? How do you determine if a display is 'retina qualified' or not? Edit: there seems to be a misunderstanding. I definitely understand what a "retina display" is, but I want to know how you can calculate whether a display is a 'retina display' or not? Example. How can I figure out whether a 20 inch display with a resolution of 1920 by 1080 with an average viewing distance of 20 inches is a retina display? (Just like that a 3.5" display with a resolution of 960 by 640 at a distance of 10 inches is a retina display). (Just like that a 9.7" display with a resolution of 2048 by 1536 at a distance of 15 inches is a retina display). How do you calculate it?