How do you automatically add column A to column B?

Answer 1

There are a few interpretations to that question, so a few possibilities are given.

You are unlikely to ever do it the first way, because realistically you are unlikely to have values in every cell in column A and every cell in Column B, that you wanted to add up into one single total. However, if you were doing that it can be done by putting this formula in any cell outside of column A and column B:

=SUM(A:B)

What you are more likely to be doing is adding just a range of figures from the two columns. So, for example if you were adding values in the first 10 cells in column A and the first 10 cells in column B, because those were all the figures you had, then your formula, which would be in a cell outside the range, could be any of the following:

=SUM(A1:B10)

=SUM(A1:A10, B1:B10)

=SUM(A1:A10)+SUM(B1:B10)

There are even other formulas you could do, but they would even be longer again. The first of those 3 is obviously the simplest.

Another possibility for the question is if you just want to add corresponding pairs of cells in each column, like add what is in A1 to what is in B1, and what is in A2 to what is in B2 and so on. That is easy enough to do. In cell C1 you could put the following formula:

=A1+B1

Then you would copy that formula into C2 and C3 and so on, and each formula in turn would add up the corresponding pairs.