Formula/VBA Help

sherikhan88 Glad it worked. The part of the formula you refer to is just to "reset the calculation in column F when the product code in column A changes AND there's nothing more to be fulfilled. The N() function allows you to reference text fields in calculations. Entering E2-E1 would result in an error as E1 contains a text, i.e. the column header. Wrapping E1 in N(  ) returns zero in this case. Alternatively, you could use SUM(E2,-E1) as sum ignores texts. whatever you prefer.

To understand what --(A2=A1) does, just enter it in an empty cell on row 2, with an= sign in front, of course, and drag it down.