I *think* you're asking to add all the values in column C that are on rows
where the values in column A and B are the same. If so,
=SUMPRODUCT(--(A1:A4=B1:B4),C1:C4)
should do it (for 4 rows; you can change the 4 to the number of rows you've
got). Note that the comparison is case insensitive, so that if A and B are
teacher and TEACHER, the value in column C of that row would be included in
your sum.

"Alpha Bravo Charlie" wrote:

I need to add the values in column "C" If the values in Column "A" are the
same and the values Column "B" are the same. How can I do it ? In the example
below I want to sum the column "C" if A1=A2 and B1=B2. I have thousands of
rows so I want to do it in one shot. What should be the formula??? Please help

A B C
Engineer USA 1000
Engineer USA 100
Engineer USA 300
Doctor Canada 500
Doctor Canada 4000
Doctor China 300
Doctor China 100
Teacher France 200
Teacher Belgium 250