The rule of thumb for determining the size TV that will provide the most view pleasure is to determine your viewing distance. Measure the seating to the spot where your television will sit and then convert to inches if you measured in feet (5ft x 12=60inches). Divide that number by 3 and that should be the approximate size television for that room. (60/3=20 in television). However this is not written in stone, you should always purchase what suits your taste.