Compare LCD screen size of standard and widescreen monitors

Nowadays there are 2 main flavours of LCD screen monitor, namely:

• Standard panel with aspect ratio of 4:3, shape similar to the screen of CRT monitors
• Widescreen panel with aspect ratio of either 16:9 or 16:10, which is the current major trend

Many might not aware that there are actually 2 types of aspect ratio for the widescreen monitor. The 16:9 aspect ratio is commonly used for television, while the longer shape 16:10 aspect ratio is more common in computer monitors.

You might have noticed that the widescreen monitor looks smaller than the standard monitor with same dimension measured in inches. The is because the measurement is on its diagonal. Widescreen panel has a longer diagonal, compared with the standard panel of same height. In other words, widescreen panel will have a shorter height than standard panel of same diagonal length.

Using some basic trigonometry calculations, I have come out with the following table to compare the estimated dimension (height x width) of  the 4:3, 16:9 and 16:10 screens.

The theory is simple. Given the aspect ratio, we can find out the diagonal angle with their reverse tangent. Once we know the diagonal angle and the diagonal length of a screen, we can calculate for its height and width.

As we can see from the above table, a 23" 16:9 panel and/or a 21.5" 16:10 panel is having about the same height as a 19" standard panel.

With a shorter height, while you can enjoy a wider screen view, you probably need to do more scrolling for vertical display, as less line is shown in the widescreen.

How will be the overall viewing area then? With the above information of their height and width, it is not difficult to calculate and compare their viewing area, as shown below:

Hope that these 2 comparison tables can help you to decide and get a monitor of your right expectation.