Using the "--" is slightly more efficient.

Try this:

A1 = west
B1 = blue
C1 = 100

Enter both of your sample formulas and they both return 100. Now, change C1
to "X" and see what happens.

--
Biff
Microsoft Excel MVP


"Ollie4" wrote in message
...
so what does
sumproduct(--(A1:A1000="West"),--(B1:B1000="Blue"),C1:C1000)
deferrer from
sumproduct((A1:A1000="West")*(B1:B1000="Blue")*(C1 :C1000))?