Is there a faster substitute for SUMPRODUCT formula?

[moccasinus]

Hi, is there a faster substitute for SUMPRODUCT formula?
Went through some forums etc. and found only that SUMIF could be a substitute.
But I can't get it work for me, I guess probably because I have 'transpose' in 'sumproduct'.
The formula I want to speed up: {=SUMPRODUCT(Sheet2!C$3:C$104;TRANSPOSE($B4:$CY4))}
There are approx. 800 rows x columns for weeks of the remaining year

 

[Mary90]

Sumproduct is a great formula and most likely the fastest way to do what you need. Transpose makes it an array and that is where your speed becomes an issue...