Hi!

Try this:

=SUM('Service Invoice (1):Service Invoice (45)'!D29)

Any sheets (tabs) that are physically located in between Service Invoice (1)
and Service Invoice (45) will be included in the calculation.

Biff

"Anakin7279" wrote in message
...
I am working on a big excel sheet, and I am kinda new at it. How can I get
a
sum of the values on 45 different excel sheets? I can only get the sum of
about 15 sheets for so before it says that my formulat is too long. Here
is
an example of the formula: =SUM('Service Invoice (45)'!D29+'Service
Invoice
(44)'!D29)
I need to get the sum of cell D29 from sheets 1-45.

thanks for your help