Definition: Android DPI

(Android Dots Per Inch) In Android devices, there are seven categories of screen density measurements that developers must be aware of, as follows:

                     Icon      Ratio
           Approx.   Size     (DPI to
 Category   DPI    (Pixels)    Pixels)

  ldpi      120     36x36      0.75
  mdpi      160     48x48      1
  tvdpi     213     64x64      1.3
  hdpi      240     72x72      1.5
  xhdpi     320     96x96      2
  xxhdpi    480    144x144     3
  xxxhdpi   640    192x192     4

  l=low  m=medium  h=high  x=extra