Hi Frank,

Thanks for your help. The formula works but I am unclear on the non
classical use of Sumproduct. Looking at the web page you cite an example to
count the number of Ford cars sold in June
=sumproduct((a1:a10="ford")*(b1:b10="June")). However there are 4 instances
of the word Ford in column A and 7 instances of June in column C so why does
return a value of 3 (which is correct for the number of Fords sold in June)
rather than 4*7=28?

Sorry if I am being stupid.

Thanks,

Danny