Why are computer monitor sizes measured diagonally?

[rgshankar76]

Hi

would like to know if some body can thro light on...

Why the Computer monitors Sizes are measured diagonally ?

 

[fargoth]

well, the ususal 3:4 aspect ratio (which had to do with the size of the negative in 35mm movie film after you subtracted for the perforations needed to pull it through a projector)
makes it very elegant to use diagonal length as the indicator of the size of the screen - instead of wrtinig both x and y, you can use d, and get x by dividing d by 5 and multiplying by 4, and you'd get y by dividing it by 5 and multiplying by 3... so an integer diagonal will get you an integer width and an integer height.
this convension has started in the 1940's,
with the introduction of HDTV it became more confusing, 9:16 doesn't give integers, and the area of the screen is deifferent for the same diagonal size in 3:4 and 9:16... but you can't chnage old habits.

 

[Moonbear]

So, yeah, the "dumb" answer is that's because TV screens are measured diagonally, so the same convention was carried over to monitors (unlike fargoth's eloquent explanation of why the convention originated for TVs). And, I find it rather frustrating that they've carried over the same convention to screens (monitors and TV) with different aspect ratios, because it no longer gives you a good idea of what size screen you're really going to get. Adding a few inches to the sides without increasing the height doesn't give you any larger text or images, it just allows you to fit more of them side-by-side. At this point, I'd prefer getting at least the height dimension.

 

[turbo]

At this point, I'd prefer getting at least the height dimension.

I've got a regular old CRT TV, so I prefer watching movies on my wide-aspect 20" LCD monitor, listening to my Klipsch speakers and subwoofer. It beats the pants off the TV for resolution and clarity and the sound is great. The extra width is also handy for keeping Outlook Express and a browser active and visible at the same time. And with this monitor, you can rotate it 90 degrees and switch the video card output from landscape to portrait in seconds, giving you the extra height that you want. The monitor is from Dell, but other seller have models with similar specs.

 

[star.torturer]

beter to get a average or absolute resolution and dimentions tahn diagonal dimension