You can change the kind of calculation used in PivotTable value fields so instead of its number, you see a percentage of a total, a running total, the difference from another value, or its rank.
Right-click the value field in the PivotTable, and then pick Show Values As.
Pick the option you want, such as % of Parent Total, or % Difference From.
To show calculations side by side with the values they’re based on (for example, to show the % of Grand Total next to the subtotal), first you need to duplicate the value field by adding it more than once. In the Field List, drag the field you want to duplicate to the Values area, and place it right below the same field.
In the example shown above, three value fields were added a second time to the Values area; they have "_2" appended to their names. Below, the "Sum of 1/1/14" field is shown twice in the PivotTable report, so you can see the value for each city and their parent (the East or West region). You also see the percentage of the grand total for each region (in rows 6 and 9).