SUMIF formula for two variables in two columns

[Guest]

How do i create a SUMIF formula for two variables in two columns?
I have a finance spreasheet and i want to add the cost of all of a certain
type of item from a certain week. Do I use the AND function and SUMIF? How
do I fit the AND formula in?

 

[Rob]

Hi,

I posted a similar question and went for Sumproduct, have a look at my
posting and replies of yesterday.

 

[Dave Peterson]

Here's a response to a similar question:

=sumproduct(--(a1:a100="UO"),--(b1:b100="Creative Technology"))

Adjust the ranges to match--but you can't use whole columns.

=sumproduct() likes to work with numbers. The -- stuff changes trues and falses
to 1's and 0's.

Bob Phillips explains =sumproduct() in much more detail here:
http://www.xldynamic.com/source/xld.SUMPRODUCT.html

And J.E. McGimpsey has some notes at:
http://mcgimpsey.com/excel/formulae/doubleneg.html