Pixels per inch calculation

Many people have complained that text on new LCD panels are too small. Here is a chart that shows the ppi numbers of common screen sizes. A number between 105-110 seems to be the sweet spot.

Screen Name	Screen	Width	Height	Diagonal	PPI
15.4" WUXGA+ (1920x1200)	15.4	1920	1200	2264	147
15.4" WSXGA+ (1680x1050)	15.4	1680	1050	1981	129
14.1" SXGA+ (1400X1050)	14.1	1400	1050	1750	124
14.1" WXGA+ (1440x900)	14.1	1440	900	1698	120
14.1" WXGA (1280x800)	14.1	1280	800	1509	107
14.1" XGA (1024x768)	14.1	1024	768	1280	91
13.3” WXGA+ (1440x900)	13.3	1440	900	1698	128
Macbook Air	13.3	1280	800	1509	113
12.1" XGA (1024x768)	12.1	1024	768	1280	106
Dell 19” LCD (1280x1024)	19	1280	1024	1639	86
Samsung 22” Wide	22	1680	1050	1981	90
Samsung 24” Wide	24	1920	1080	2203	92

The downside of adjusting font sizes is that some application's GUI will look weird with large fonts. Well, then design better GUIs to accommodate both small and large fonts. Personally, I don't mind adjusting font sizes on screen with higher resolutions. Ctrl-plus and Ctrl-minus are easy enough for me in Firefox.

As the LCD and LED panel technology advances, the ppi number will just keep going higher and higher. I know IBM has already developed panels with 200 ppi for medical use, which cost $10000 each. I look forward to having one of those panels on my laptop one day. The screen will be so sharp that it should look like ink on paper.