Summing Based on Part of a Control Cell

Eszter has a long list of cells in column A that contain a series of mutation codes, such as "AKT 142" or "BRAF 1975." In column B are values associated with these mutation codes. She needs a formula that will sum the values in column B for which the corresponding mutation code in column A begins with the same sequence, as in all those beginning with AKT or BRAF. Eszter suspects this can be done with the SUMIF function, but she doesn't know how to make it pay attention to only the first part of the mutation code.

There are many ways you could approach this problem, but in this tip, I focus on only three potential solutions.

Using a Helper Column

If your worksheet layout allows, you could add a helper column that contains only the first portion of the mutation codes. Since your mutation codes are in column A, you could insert the following formula in the first cell of your helper column:

=LEFT(A1, SEARCH(" ",A1,1)-1)

Copy it down for as many cells as necessary, and you end up with the helper column containing everything in the mutation codes before the space. You could then use your desired SUMIF formula to sum based on the contents of the helper column.

Using SUMPRODUCT

A rather unique approach to solving the problem is to use the SUMPRODUCT function. Let's say that you put, in cell E1, the preface code you are interested in. (So, for instance, you might put "AKT" into cell E1.) You could then calculate the desired sum by using the following formula:

=SUMPRODUCT(--(LEFT(A:A,LEN($E$1))=$E$1) * B:B)

This works because SUMPRODUCT examines whether the leftmost portion of a cell in column A matches whatever you put in cell E1. If it does, then the comparison returns 1; if it doesn't, it returns 0. This is then multiplied by the corresponding cell in column B and summed.

Using SUMIF Directly

Perhaps the cleanest approach is to simply use SUMIF directly. You know, from using the helper-column approach, that you can use SUMIF to look at the contents of a cell and then selectively sum another column. You do it in this general manner:

=SUMIF(Check_Range, Criterion, Sum_Range)

Thus, if you wanted to sum values in column B based on what is in column A, you could do the following:

=SUMIF(A:A, "AKT", B:B)

This would, of course, only match those cells in column A that contain just AKT. This is not Eszter's situation, though—the mutation codes in column A contain more than just AKT. This is where the use of wildcards in the criterion specification comes into play. All Eszter needs to do is to add an asterisk, in this manner:

=SUMIF(A:A, "AKT*", B:B)

Now SUMIF returns the proper sum based only on those cells in column A that begin with the letters AKT. It doesn't matter what follows the AKT characters in each cell because the asterisk says to Excel that it should "accept anything that follows those three characters."

You could even make this approach more general in nature. Let's assume that you put the desired preface code (the one on which you want to sum) into cell E1. You could then put the following into cell E2:

=SUMIF(A:A, E1 & "*", B:B)

Now, if E1 contains "AKT" you end up with a sum of values for that preface code. If you change E1 to "BRAF" then you get a sum for that preface code, without a need to change the formula in E2.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (13614) applies to Microsoft Excel 2007, 2010, 2013, 2016, 2019, Excel in Microsoft 365, and 2021.