There are a number of factors to consider when trying to determine what size screen your Plasma Television should be. The televisions come in a number of different sizes. Plasma monitors are measured diagonally across the screen, as are other television sets and monitors. Plasma screens start at 32" and increase in size up to 63". The typical sizes are 32", 40", 42", 46", 50", 61", and 63". The most popular screen sizes are 32", 42" 50" and 61". Screens smaller than 32" are considered LCD monitors
Probably the most important factor to consider before going out to purchase any new television is determining how much space you have to house it. When inserting the unit in a space allow at least 3" of open space at the top and adequate ventilation space behind the unit to allow heat to escape. Remember that most plasma TVs do not have built in speakers but do offer some type of attachable side speakers, so allow an extra 3-6" on each side if you plan to use these.
The next factor to assess is the viewing distance. In other words, how far you will be sitting from the television screen. Generally, you can use these guidelines to determine what screen size will best fit the needs of your room. For televisions between 32-37" screens may be viewed from 6 to 10 feet. The best viewing picture for a 42" plasma display will yield a distance from 10-14 feet. A 50" plasma display will look best from 12-16 feet. For any screen larger than 60" you should allot at least 15 feet for optimal viewing.