Bernard Lechner is an award winning television engineer. At RCA he was heavily involved in the development of HDTV. Lechner researched the typical distance between a viewer and their television screen by taking measurements in many American homes. The median distance complied from all his data came out to 9 feet. This measurement is now called the Lechner distance.
Your viewing distance based on Lechner’s analysis is very likely to be 9 feet. There are two standard HD broadcast resolutions 720 lines and 1080 lines. The following are the minimum screen sizes that will let your eyes resolve all the detail at the Lechner distance, one for each HD broadcast resolution.
For a 720p display it’s a 46″ screen size.
For 1080i or 1080p display it”s a whopping 69″ screen. All screen measurements are diagonal inches.
A smaller display for each given resolution will not allow your eyes to perceive all the detail that appears in HDTV.
For the maximum viewing distances for different screen sizes see my exclusive Viewing Distance Chart at