Its easy.
Click the arrow next to the pivot table toolbar.Select "FORMULAS" and
click"CALCULATED FIELD".The rest could be done with Microsoft Help

Sune Fibaek wrote:
Hi

A quick questions about pivot tables:

I have two data fields. One vith values from last year, and one with values
for the current year. Both are shown as % af column. Now, I would alså like
to show the difference in percentage points. Is it possible to make a
calculated field that subtract one value from another and show the difference
in percentage point?

Can anyone give me a hint here?

Thanks.

/Sune