I currently have a macro that copy pastes a formula based on a predetermined
cell range. Is there a way to create a loop that will find cells that have
values in Col B and Col C and paste the formula in Col N.

Macro Example: (Replace "=Range("N2:N100)) with loop.

ActiveCell.FormulaR1C1 = _
"=IF(RC13="""","""",SUMIF(R2C2:R500C2,R2C13:R100C1 3,R2C3:R500C3))"
Range("N2").Select
Selection.AutoFill Destination:=Range("N2:N100"), Type:=xlFillDefault
Range("N2:N100").Select
ActiveWindow.ScrollRow = 1

Thanks