I don't have such a technical answer. What I do have is experience. The TV in the living room is 32 inches, around 5-6 feet viewing distance. We wanted to buy 1 for our bedroom. The viewing distance is similar and the salesman highly recommended 32 incher. But i still went ahead and bought the biggest 1 i could fit in the room without creating a mess of my furniture - a 55 inch Full HD. I am so used to watching the'BIG' screen, i no longer use the TV in the living room at all. It's especially great to watch streaming movies, with dimmed down brightness and lights switched off, comfortable on your bed.