Calculate a running total of a column of cells in Excel

If you have a column of numbers and you want to calculate a running total of the numbers alongside, you can use the SUM() formula combined with a clever use of absolute and relative references.

Imagine your spreadsheet has values in cells A2 through to A20. You want to put a running total in column B.

In cell B2, enter the following formula:

=SUM($A$2:A2)

This will put the value of A2 into B2. Remember that $A$2 is an absolute reference. This means that anywhere you copy this formula, it will always refer back to A2.

Then, copy this formula and paste it into cell B3. The formula should now look like this:

=SUM($A$2:A3)

This will put the sum of A2 and A3 into B3. Note that, as promised, $A$2 hasn't changed even though you have copied the cell from one place to another. On the other hand, A2 was a relative reference in the previous cell, so it changed from A2 to A3 when you copied and pasted the formula from B2 to B3.

Once you've verified that this works as described, you can then copy the formula into each cell from B2 to B20. The final cell, B20, will contain the total of all the numbers in cells A2:A20.