Thank you Bob, you are a great help.

While your formula works, I am still a little uncomfortable about the use of
arrays of different dimensions (A1:A10 and C1:Z10) in a single array
formula. It is because according to the Excel XP help file, all arrays in an
array formula should have the same dimensions.


"Bob Phillips" bl...
=SUM(IF(ISNUMBER(C1:Z10),IF((A1:A10=1)*(B1:B10=1), C1:Z10,0)))

as an array formula, commit with Ctrl-Shift-Enter


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HTH

Bob

"robot" wrote in message
...
The formula works! Thank you both for your replies.

However, some of the cells in the region C1:Z10 include text but not
numbers. I would like to treat them as zeros, so I tried

=SUMPRODUCT((A1:A10=1)*(B1:B10=1)*(IF(ISNUMBER(C1: Z10), C1:Z10, 0))

However, the formula always returns zero. What can I do?


"Mike H" ...
Hi,

I'm not sure I fully understand but maybe this

=SUMPRODUCT((A1:A10=1)*(B1:B10=1)*(C1:Z10))

Mike

"robot" wrote:

I have a worksheet with data in the region C1:Z10.
I want to sum over everything in the region C1:Z10 which meets certain
criteria for columns A & B (more specifically: equal to 1).

Also, I don't want to create an extra column of sums for the region.
All I
want is a formula.

I know I can use
SumProduct((A1:A10=1)*(B1:B10=1), C1:C10 + D1:D10 +...) , but that's
too
clumsy.

What can I do? Suggestions are most welcome!