=SUM(IF(A1:A29="A",IF(B1:B29=--"2001-01-01",C1:C29/0.029,C1:C29/0.03)))

=SUM(IF(A1:A29="B",IF(B1:B29=--"2001-01-01",C1:C29/0.029,C1:C29/0.03)))

etc.

which are array formulae, they should be committed with Ctrl-Shift-Enter,
not just Enter.
Excel will automatically enclose the formula in braces (curly brackets), do
not try to do this manually.
When editing the formula, it must again be array-entered.

--
---
HTH

Bob


(there's no email, no snail mail, but somewhere should be gmail in my addy)



"Jason" wrote in message
...
Awesome, both of those formulas worked great. Thanks! I have one
followup
question. I have the following data:

Category Date Amount
A 11/1/01 100.00
A 1/1/00 100.00
B 12/31/04 200.00
C 1/1/00 300.00

As stated before, I have the formula to sum the values in the fields and
divide the ones with invoice date before 1/1/01 by .03 and the ones after
1/1/01 by .029. However, is there a way to incorproate another formula
that
will only calculate the ones in category A, then in a sepearte cell
calculate
the ones in category B and so on and so fort.

Thanks,

Jason