iPad, iPhone, Kindle, Xoom: Pixel Dimension, Resolution, Density

, 2012-03-11

After staring at a tablet screen for a couple hours, now looking at my PC screen, the resolution is so coarse!

By the way, the term “resolution” usually is used incorrectly. Here's clarification.

Pixel Dimension = number of pixels on the screen, width and height. i.e. iPad has 1024 × 768 pixels. (most people (incorrectly) call this “resolution”.)
Pixel Density = screen resolution (how fine it can display something). Measured in “pixels per inch” (PPI). (this should be what “resolution” means.)

Here's some examples of pixel dimension and density:

Name	Pixel Dimensions	PPI	Screen Ratio
iMac 21.5″ amazon	1920×1080	102	1.78
MacBook Pro 15″ amazon	1680×1050	128	1.6
IPad 2 amazon	1024×768	132	1.33
IPad 3	2048×1536	264	1.33
Samsung Galaxy Tab 10.1 amazon	1280×800	149	1.6
Samsung Galaxy Tab amazon	1024×600	170	1.6
Amazon Kindle 1 & 2	800×600	167	1.33
Amazon Kindle DX	1200×824	150	1.46
Kindle Fire amazon	1024×600	169	1.71
Motorola Xoom amazon	1280×800	160	1.6
BlackBerry PlayBook amazon	1024×600	169	1.7
IPhone 4 amazon	960×640	326	1.5

In general, display for PC usually have a density of 80 to 120 PPI. While tablets is 130 PPI, 150 PPI, phones got 300 PPI.

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