Sum of diagonal products - excel

Question

I am looking to get the sumproduct but only for specific diagonals in an array. My setup is like below and the yellow highlighting should give an idea of how the formula should calculate
As text:
Years Rates 0 1 2 3
25 0.16 25 24 23 22
26 0.11 26 25 24 23
27 0.12 27 26 25 24
28 0.13 28 27 26 25
29 0.17 29 28 27 26
30 0.16 30 29 28 27
Years Sum of products
25
26
27
28
29
30
Note, the table on the right dictates how many years to include, so if the table were extended to include 4 years then 0.17*4 would need to be included in the sum product for 25
What is the best way to do this? Ideally not a CSE formula/ VBA. The actual table is much bigger, so I might need to be conscious of speed too.
I intend to edit this with what I came up with but I hope to see some different ways of doing this so I hope it's okay that I hold off for now.

Answer 1

Simply:
=MMULT(G4:J4,B7:B10)
Regards

Answer 2

You could give this CSE a try, maybe it's not as bad (even though you don't want one)
=SUMPRODUCT(B7:B10,TRANSPOSE(G4:J4))

Answer 3

I think a 'CSE' formula will be best even though you'd prefer not to.
With the first formula in B11 and the setup as in your image, (with the 0, 1, 2, 3 in D1:G1, the word "Rates" in B1, and the array in D2:G7 etc)
{=SUM(IF($D$2:$G$7=A11, $D$1:$G$1*$B$2:$B$7, 0))}
and drag down

Answer 4

This is the best way I can find, without using a CSE formula
=SUMPRODUCT(--($C$2:$F$7=$A11),$B$2:$B$7*$C$1:$F$1)
The first array is n x m in size and the second array is the product
of a n x 1 and 1 x m array, which is converted to an n x m
array. This provides SUMPRODUCT with two identically sized arrays as required.