As of September 4, 2012, the most popular device densities for Android devices accessing the Google Play market are normal-hdpi (51.9%), normal-xhdpi(22.3%), and normal-mdpi(11.4%). Mdpi is considered the baseline, as it is a 1:1 screen-pixel to device-pixel ratio. And by device-pixel, I’m referring to a physical unit of measurement on the device. If you’re a newbie android designer, mdpi is a great place to start in terms of density, since it’s how we work with pixels in photoshop, fireworks, etc. Hdpi is a 1.5:1, and can be thought of as a HD (high-definition) display. And xhdpi is 2:1, much like Apple retina displays. . The normal mdpi is based on a 160 dpi screen, which again is the same as a single pixel unit in your graphics software.
Here’s a quick breakdown of the dpi measurements for the different pixel densities:
ldpi – 120dpi
mdpi - 160 dpi
hdpi – 240 dpi
xhdpi – 320 dpi
The most popular screen sizes according to the dpi chart above are the following resolutions:
Normal hdpi - 480×800 (720×1200 in design)
Normal hdpi - 480×854 (720×1281 in design)
Normal xhdpi - 640×960 (1280×1920 in design)
Normal mdpi - 320×480 (in design)
So, based on the data above, a good approach for your Android design is to target a 480×800 (720×1200 in design) screen size, which covers more than 50% of the market. If you need to create mockups for the full gamut of Android devices, starting with a max resolution of 640×960 (1280×1920 in design) and resizing down to 320×480 (normal resolution) should give you coverage of about 85% of the Android market.
Original blog post: http://www.uifuel.com/supporting-multiple-device-resolutions-for-android/