Creating this question, and providing the answer as well.
On new documents created with the default template, the default unit is either in (US) or mm (Europe).
As I work mostly on documents which are displayed on screens, I’m mostly interested in having them measured in pixels (the export to png format is also facilitated).
How to change the unit of the default document?
Answer
Changing the unit used in a new document is done by configuring a default template:
In Windows the default template is a document that is saved as:
%appdata%\inkscape\templates\default.svg.
This folder is actually:
C:\Users\Me\AppData\Roaming\inkscape\templates
in Windows 7, and is empty.
See more details on this answer related to changing the default size.
Attribution
Source : Link , Question Author : mins , Answer Author : Community