Sum a column at the bottom of it

In Google Sheets, how do I get - at the bottom-most cell of a column - the sum of each cell (except for row 1, the header) above in that column? Keep in mind, I may add rows in the future.

• Thanks "user0". What would it be, for that same case, if I want to sum up the column ONLY if the sum is greater than zero? (I just don't want to see 0's when the column is blank. Also, I would like this to apply on all columns from C onwards, and I want to be able to add rows anywhere, (even before the last row - so, plain SUM function wouldn't fit for me.)) – Bilha Jul 25 at 6:45

There are various ways how to solve this. The most simple would be to use dragging SUM: Then all you need to do is insert new rows inside of the SUM range so it would automatically expand as needed: As a next-level move, you can use ARRAYFORMULA with INDIRECT where you can use ROW()-1 to always get the range from A2 cell to the row where this formula resides minus 1 row:

=ARRAYFORMULA(TRANSPOSE(MMULT(
TRANSPOSE(INDIRECT("A2:C"&ROW()-1)),
ROW(INDIRECT("A2:A"&ROW()-1))^0))) 