LCD vs CRT

LCD monitors are not the same size as CRT monitors, in fact your viewing screen is actually larger! Monitor measurements are measured diagonally. Since the advent of the television, this has been the industry standard for screen measurements. When computer monitors hit the scene, the measurement became the diagonal measurement of the tube itself, not the actual viewable screen. When you look at your monitor, there is a plastic box which houses your CRT tube and other components, but when you look at the front of your monitor, there is probably an inch or more of framework around your picture tube. This hides the rest of the CRT tube which is enclosed within the box.

Now take a ruler ot tape measure, and measure the actual image you are viewing, measure diagonally, and you will see that the actual measurement is smaller than the monitors claimed size. For example, my 19 inch CRT monitor, measuring the actual image from the bottom left hand corner of the picture to the upper right hand corner is actually 17.25 inches, or in other words, only .25 inches larger than a 17 inch monitor, if the monitor measured the actual viewing screen. This is where the LCD measurement comes in.

LCD monitors are measured by actual viewable area of the screen. They do not have a large rounded out tube beyond the screen, it is a flat panel of Liquid Crystals behind which are a series of tube lights that shine through the color crystals to illuminate your display. A 17 inch LCD monitor is 17 inches diagonally, a 19 inch monitor is 19 inches diagonal or about 1.75 inches larger than my example of the CRT tube.

If you are considering a wide screen monitor, you should read this for information about how the wide screen affects the picture size also.