To create a calculated field:

Select a cell in the Pivot Table
On the PivotTable toolbar, choose PivotTableFormulasCalculated Field
Type a name for the formula
In the formula box, type: =
In the Field list, double-click the After field
Type a minus sign: -
In the Field list, double-click the Before field
Click OK,

emlouise wrote:
I have a pivot table set up in that it displays data with values before and
after an event. I would to be able to calculate the difference between the
two values in a separate column within the pivot table. Does anyone know how
to do this or if this is possible? It is using Excel 97 I have tried using a
calculated field but it does not return a sensible answer


--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html