Choose Standard or Calculated measure. A standard measure is based on a simple expression, like views; calculated measures typically involve performing an operation on two measures, such as views per session.
Create the measure, selecting build expressions and what you want to count and display.
Give the measure a name and brief description. Descriptions are useful, and appear when you hover over a measure in the Available measures list.
Select where to save the measure:
This view only: Saved only while the view is in use. The measure is lost when you close or navigate away from the current view.
Private library: Viewable only by you. You can use these measures in other views.
Public Library: Visible to all users. This option is not visible if you do not have proper access rights.
Click Save. Once a measure is created, you can drag and drop it into the current view.