Pivottable - How to calculate, A-B=C ?

[SpookiePower]

In my pivottable I need to say "sum of salgspris" - "Sum of indkøbspris" = C, but I don't know how to do this ?
I need the last column where the profi i calculated. Someone who can help ?

[rpeare]

is your pivot table based on a table or a query?

If it's based on a query you can add a 'net' value where you could have a formula that transforms any indkøbspris to a negative value and leaves everything else alone (leaves it positive) then add that to your pivot as a straight sum.

[SpookiePower]

It is based on a table, but I think I'll try to use the query as you say.