I have developed a spreadsheet on my home computer which does a lot of
SUMPRODUCT calculating (I know this can be a slow calculating function). On
my computer the spreadsheet takes 2 minutes to do its calculating. I
transferred the speadsheet to the company I was doing work for & run the same
spreadsheet but it takes 40 minutes to do it's calculating. This was running
over a network so I tried to run on the local drive on the fastest PC there
(it is only a slightly lower spec than my machine) & it still takes 30
minutes.

The SUMPRODUCT looks up a worksheet table which Excel gets thru a query. I
have only the minimum number of lines in the table that it needs as I know
the SUMPRODUCT function takes alot more time on larger sized tables. I have
tried turning off any services that the PC was running, such as antivirus,
that could slow the PC down but it didn't make any difference. What things
should I look for to make this faster?

Below is the type of code I have in the spreadsheet.

=SUMPRODUCT((Sheet2!A$1:A$3110="Family")*(LEFT(She et2!F$1:F$3110,20)="Counselling
- family")*(Sheet2!B$1:B$3110<"
")*(LEFT(Sheet2!D$1:D$3110,1)="A")*(Sheet2!E$1:E$3 110=A12)*(Sheet2!E$1:E$3110<A13)*(Sheet2!C$1:C$31 10=C$6))

Is there another function that I could use other thatn the SUMPRODUCT
function? TIA
--
Tony