How to get cumulative totals from weekly totals (IE sum of all previous cells)?

[moeburn]

I have a CSV of my Google Adsense account. Among other things, it shows me how much money I made each week. It looks like this (hypothetical fake data):

Columns (A) & (B)
Week 1 - $2
Week 2 - $3
Week 3 - $0.25
Week 4 - $1
Week 5 - $6

I want to make a graph of my total earned $ over time, so that I can make a trendline and estimate when I think I'll reach Google's payout threshold of $100. But to do that, I need cumulative totals each week, not individual week totals, and unfortunately Google doesn't offer that calculated data. So I have to calculate it myself. Simple enough, I'll just make a 3rd column with cumulative sums, so that it looks like this:

Columns (A) & (C)
Week 1 - $2
Week 2 - $5
Week 3 - $5.25
Week 4 - $6.25
Week 5 - $12.25

Problem is, I have about 200 weeks to do, and I can't see any easy way to get a cumulative sum column without having to do it manually. I tried the auto-fill, but it took my column of:
=SUM(C1:C2)
=SUM(C1:C3)
=SUM(C1:C4)
=SUM(C1:C5)
...and Excel decided to continue what it thought was the pattern of:
=SUM(C2:C6)
=SUM(C3:C7)
=SUM(C4:C8)
=SUM(C5:C9)

Which is not what I want! So how do I automatically create a column of =SUM(C1:"This row") formulae?

[jeffreybrown]

If you lock one side of the formula it will create a running sum...

=SUM($C$1:C1) >> now drag down

[moeburn]

If you lock one side of the formula it will create a running sum...

=SUM($C$1:C1) >> now drag down

Yay that worked, thank you! I always wondered what those $ that Excel kept using sometimes were for...

[ExcelTactics]

Give this a try:

A	B	C
Week 1	$2.00	=B1
Week 2	$3.00	=C1+B2

You should be able to drag down C2 to sum as you go.

[jeffreybrown]

You're welcome…glad you have a workable solution and thanks for the feedback...

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