Pivot Table - '% of Total' question

[goofy11]

I have a Pivot Table with Inventory, % of Inventory, Sales, and % of Sales.
To get '% of Inventory' and '% of Sales' I used the Inventory and Sales
fields a second time and used the '% of Total' option. My table looks
something like this.

Category Inventory % of Inventory Sales % of Sales
aaaa $30,000 11.91% $31,000 12.31%
bbbb $20,000 8.32% $22,000 9.29%
cccc $15,000 6.38% $14,000 5.25%
etc.

What I want to do is add a 5th field (% of Sales - % of Inventory). I
realize I can enter this calculation outside of the Pivot Table, but I would
love to
have it be part of the Pivot Table because I plan to drill-down/expand the
Pivot Table and would like it to stay dynamic. I also need this because I
want to use the Top 10 feature and sort the Pivot Table by the result of this
calculation. I know how to insert calculated fields in Pivot Tables, but I
can't see how to do this using the '% of Total' fields. Is this possible?

Any guidance would be appreciated, even if the guidance is "this can't be
done".

Thanks,

Jeff

 

[fullers]

If you select your pivot table and then go to Insert>Calculated Field you can
then do the necessary calculation based on fields within your pivot.

This field will change with your pivot.

 

[goofy11]

It is true that I can do a calculated field using Inventory and Sales....the
problem I'm having is trying to do a calculation using % of Total Inventory
and % of Total Sales. These fields are not in my raw data. They were
created using the '% of Total' field option. When I try to insert a
calculated field, the only fields I have to choose from are the fields from
my raw data. % of Total Inventory and % of Total Sales are not there. Does
that make sense? I hope I'm being clear about what I'm asking for.

Do you or anybody else have further ideas?