But, ultimately, screen size should depend on a number of factors, says interior designer Linda Nolan, including how far away you’re sitting and where the TV is in the room.

For instance, let's say you have a 24-inch flat screen, 24 divided by .835 equals 28.7 inches or 2.3 feet. So, you wouldn't want to be further than 2.3 feet from a 4K 24-inch TV for the best ...