take a look he

http://www.mcgimpsey.com/excel/accumulator.html

In article ,
"Bill" wrote:

I would like to know if it is possible to have a running total using only two
cells. I have many rows of items that are tracked each week and each item
rolls up to a monthly total. What I would like is to have the following: B1:
=A1+B1, B2: =A2+b2, B3: =A3+B3 and so on. I need only the row where a change
was made (A1, A2, A3, etc.) to caculate at the time of the change leaving the
other rows unchanged. What I am doing now is taking last weeks entry and
manually adding to the monthly total for each item. I sure hope someone can
help me with this, as I make mistakes adding.