Using sumproduct with dividing and subtraction
 

I'm trying to come up with a formula where I can calculate accrued interest
based on certain criteria.
I have about 5 columns....Date Range, Principal, Interest, Invest Type,
Rate, No. of Days, Year Base (360 or 365)
and I want to come up with a formula that will calculate accrued interest up
to a specific date for certain invest types.
The Sumproduct formula seems like it would work....but I can't figure out
how to use it and have it divide by the year base.
Is there some other formula that can do this?