When supporting different screen sizes (densities) in Android often the focus is on creating different layouts for every possible screen. I.E.
Android 3.2 introduces a new approach to screen sizes,the numbers describing the screen size are all in “dp” units.Mostly we can use
smallest width dp: the smallest width available for application layout in “dp” units; this is the smallest width dp that you will ever encounter in any rotation of the display.
To create one right click on res >>> new >>> Android resource directory
From Available qualifiers window move Smallest Screen Width to Chosen qualifiers
In Screen width window just write the "dp" value starting from you would like Android Studio to use that dimens.
Than change to Project view,right click on your new created resource directory
new >>> Values resource file enter a new file name dimens.xml and you are done.