Ever wonder what the correct monitor sizes for a particular screen resolution where? This chart examines seven screen resolutions, and shows the "correct" size of monitor needed for each.
Reading the Chart
MacOS/Windows Screen Resolution: Lists seven standard hi-res SVGA screen resolutions, in pixels across by pixels down. More pixels means higher-definition displays. When someone talks about their screen "resolution," they're usually talking about this.
DPI (dots per inch): DPI refers to the number of dots (pixels) per inch on a screen. If you have a Macintosh computer (or MacOS compatible), you have a 72 dpi screen. If you have a Windows PC, you have a 96 dpi screen. DPI is also known as "resolution," although resolution is really a combination of dpi & the above.
Viewable/"Correct" Size: The diagonal size of the "correct" monitor for this resolution. This will be advertised as the monitor's "viewable" area. Chances are you won't be able to find this exact size. The closer your monitor's viewable area is to this, the closer you are to having the screen inch be the same size as a real inch.
Closest "Advertised" Size: Monitors are advertised by the dimension of their CRT, not their viewable area (probably because the CRT size is bigger). For example, the 14" screen on my desk has a 14" CRT but only a 13.1" viewable area.
Trivia: Pixel, short for picture element (also called "pels" in some Windows programs), is the smallest dot that a screen can display.
There are two charts because there are two standards for dpi in the world: the typographical standard (72 dpi), and the Microsoft standard (96 dpi).
Macintosh computers operate at the typographical standard resolution of 72 dpi. This makes it very easy to convert from pixels to points, because they're the same! This means that if you have the correct monitor size, your screen image will be the same size as what you print. There's 72 points in an inch, there's 72 pixels in an inch. Very nice.
Windows2 computers run at a standard resolution of 96 dpi, and I have no idea why (might be related to the dpi of some early CGA/EGA/VGA screens?). Because of this, objects that are displayed under Windows will appear to be 133% of their printed size. I can't tell you how many times I see students in the lab set their type size to 9 pt on a Windows workstation (appears to be (9 * 3/4) / 72 = 1/6" on screen) and wonder why it looks so tiny when printed (9/72 = 1/8" on paper).
Footnotes, revised 12-2000:
1. The 832x624 is apparently a really uncommon PC resolution, or a Mac-specific one, as you won't find it on your PC. Since Macs and PCs these days quite often use the same video hardware, chances are that both are true.
2. You will also find 96 dpi on PC hardware running non-Microsoft operating systems. For the reasons stated above, I still don't understand why 96 dpi is used. 72 dpi is much more useful for achieving WYSIWYG printed output for anything with text on it.
Printing problems? Try the black & white version of this page.
Published Oct-98, Copyright © 1998,2000 Seth Hill