The size of screen for your new TV may depend on your budget because larger screen sizes tend to lead to higher prices. However, there are various other considerations that can include where and how you want to use the TV.

Screens of 30 inches and below are generally considered adequate for bedrooms and guest rooms but too small for the main living room. Here, you need a screen that's big enough for the whole family to enjoy but not be so big that it dominates the room.

The size of screen may be determined by how close you intend to sit to the set. Sitting close will mean you don't need such a big screen although getting too near might make the picture look poor. The availability of windscreen HD TVs has, however, changed the rules in terms of viewing distances.

The usual rule of thumb for standard TVs is that you should sit no closer than twice the diagonal measurement of the screen. Thus, for a 30 inch screen, you should be no nearer than five feet from the set. The improved picture standard and changed proportions of widescreen high definition TVs mean that you can sit closer with no noticeable loss of quality. The general recommendation is that you can approach within 1.5 times the screen's diagonal measurement but should not be further away than three times the screen size. Being too far away means you may lose out on the immersive, theatre-like picture that these sets deliver.

The size of screen you choose may also determine the type of display you can have. Forget the old-style CRTs because these belong to the past and the future is flat panels. The smaller sizes tend to be almost exclusively LCD screens although LED displays are also available. Plasma screens are normally used only for the larger sizes and there are also the less common rear projection sets.

LCD has ultra fast refresh rates for smooth movement and better power consumption than plasma screens. LED is based on an LCD display but has a LED-based back-lighting system that allows thinner panels, deeper blacks with no loss of brightness and the lowest power consumption of all. Plasma TV has much higher refresh rates that result in no motion blur and smooth movement. It also gives darker blacks, more vivid colours and wider viewing angles than other types.

The size of screen you choose will determine not only the price you pay but also the type of display available.