The benefits of a 4K screen become most noticeable when you sit at a distance of around one to 1.5 times the size of your TV. At that distance, you'll be able to see the extra detail that 4K resolution offers compared to a 1080p high-definition screen. For a 65-inch 4K TV, the ideal viewing distance should be between 5.4 and 8.1 feet from your TV.     You can of course sit further away and still enjoy a 65-inch 4K TV, but that range will yield the best level of visible detail. Otherwise, you'll want a bigger screen to get the full benefits of 4K.