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 most typical sizes are: 37", 42", 43", 50", 61", and 63". Most screens smaller than 37" use LCD Panel technology, and anything larger than 63" are typically rear-projection televisions.
If you have a set installation in mind, the first stage in selecting the desired plasma screen size should be to measure the space it's going in. When recessing 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 to allow an additional 3-6 inches on either side of the monitor if you wish to attach speakers to your plasma TV.
Size of Room/Viewing Area
Make sure you have adequate viewing space between you and the TV. With Plasma TVs becoming more and more popular - and cheaper - these days, the temptation to purchase the largest screen possible is hard to pass up. However, you must have the proper distance to have the most pleasing viewing experience.
Rough recommendations are as follows: 32-37" screens may be viewed from 6 to 10 feet. A 42" plasma display may be optimally viewed from 10-14 feet. A 50" plasma display will look best from 12-16 feet, and you should have at least 15 feet to work with when installing a 61-inch or 63-inch plasma screen.