Martin,

Do your named ranges refer to whole columns? If so, there is your problem as
SUMPRODUCT cannot handle whole columns, only part columns.

Also Weeknum doesn't seem like a smart name for a range, it is an Analysis
Toolpak function.

--

HTH

RP
(remove nothere from the email address if mailing direct)


"Martin B" wrote in message
...

Thanks for responding but I can't get the formula to work, keep getting a
#NUM error message telling me the cell I am referring to containing the
week
number contains a constant. Any ideas?

Martin