How is monitor resolution measured for “HD” monitors?

By HD I mean my mid-2011 17" macbook pro screen, the Dell Ultrasharp 30", or the 27" apple cinema display. All of these have a really high resolution, and I'm wondering what this is called. DPI?

I'm trying to find 2x 23" monitors with the SAME "resolution per square inch" as these monitors above. I'm hesitant to say "the same resolution" because obviously the resolution on my 17" mac (1920x1200) wont be the same as what it will be on the 23" screen (which i have no idea), even if the screen shares the same very small and clear picture.

Hopefully htis is making sense, he just wants 2 monitors which are extremely sharp and clear with high resolutions, not the crappy 1080p. Hes an accountant so response times arent important for games or anything.

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The resolution will be the same, the density won't. – Oliver Salzburg Mar 24 '12 at 14:55
how do I get the same density as my mac monitor, but in a 23" monitor (whatever resolution that may be). What am i asking for when i go to the store? – Tallboy Mar 24 '12 at 14:56

First of all, if you have a specific resolution (1920x1200), no matter how big the display is, the resolution is always the same and the image will always be the same (just the size changes, not the contained information).

If you want an image to be sharper you either need to increase the density (and, thus decrease the size of the display) or increase the resolution.

So if you want a 23" screen with the same density as your 17" screen, then it can't run on 1920x1200. It has to have a higher resolution. Well, if you have a display with a 2560x1440 resolution, nobody is stopping you from only sending 1920x1200 to it, but that wouldn't really be in your best interest.

Wikipedia has a great comparison table for pixel density of Apple displays.

Let's go for some math (if I can get it right):

MacBook 17" 1920x1200:

Pixels per inch: sqrt( 1920 ^ 2 + 1200 ^ 2 ) / 17 = 133.185616

Looking back at our Apple Display table... None go that high. And it's not surprising if you think about it. I guess, your best choice is an iPad3.

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What do you mean fidelity? – Tallboy Mar 24 '12 at 15:10
And so do they make 23" monitors with the same density as my macbook pro or the cinema display? – Tallboy Mar 24 '12 at 15:10