Android: EditText widget auto-size : Is a there a method in XML by which I can autoset the size of a widget (as 'EditText') automatically?

I'm asking this because, setting fixed values for width and height, I'm afraid not to respect the screen size of any device in which my app will live.


For example:

I need to set a width that will take a margin of 15dp from left edge, regardless from the device (so the screen size) used.

Someone can help me?