A kind of sumproduct formula but subtracting a value from each value in one of the arrray;

Hi everyone,

Can anybody help me simplifying the following formula:

'=((F17-F17)*D17)+((F17-F16)*D16)+((F17-F15)*D15)+((F17-F14)*D14)+((F17-F13)*D13)+((F17-F12)*D12)

Its basically the sum product of column F time column D...however, all the F values are first subtracted from the last F value; Obviously I could just have an extra column to calculate all the new "F" values the issue with that is that I want to be able to drag down the formula and so the value F17 changes for each last value in column F...Hope this explanation is clear enough.

Yes, that almost seems to work...but doesn't really give me the right value...can you take a look a the example I posted? I'd like to be able to just copy down the formula and it just adds on the new rows I need...Thanks! Really appreciate your help!

Awesome!!! Works great! Thanks