What Size HDTV Should I Buy?
The short answer is if you have a small room and your sitting close to the TV, then you need a smaller HDTV. On the other hand, if your room is large and your sitting farther back, then you can go with a larger HDTV.
Rule of Thumb: Measure the distance in feet between where you want to place your HDTV and where you will be sitting. Now take that measurement and times it by 3 and also by 5. This will give you your minimum and maximum size HDTV
Example:
The distance between where you want to place your HDTV and your chair is 9 feet. Take 9×3=27 so your minimum size would be a 27 inch TV. Now take 9×5=45, so your maximum size would be a 45 inch HDTV
Of course the other rule, which you should ignore, is that you buy the biggest one you can afford.

September 11th, 2008 at 6:22 am
[...] they plan to place the TV, and the seating area is at best, 6 feet away. Using the 3 - 5 rule (see earlier post on the 3 - 5 sizes rule) the biggest size should be a 30 inch [...]