How to fill in missing data with a simple formula

In this video I'll show you a way to quickly add missing data to a worksheet. It's a simple technique using a very basic formula, and it's a beautiful example of the power of relative cell references.

Sometimes you get a set of data that isn't complete because it's been organized like an outline, with main headings and sub-headings appearing just once at the start of a new section.

This isn't a problem for humans because we can see and understand the overall structure of the data.

But it won't work if you want to analyze the data using filters, or pivot tables, or even conditional formatting. To slice and dice data with these tools, you'll want a full set of values in each row.

But entering this kind of missing information manually in a large set of data is tedious work, even using shortcuts.

Fortunately, as long as the data is well organized, you can use a simple formula to add missing values.

Let's try it with this data.

To begin with, select the data. If I put the cursor into the last column, which contains a full set of values, Control-A will do the trick.

Next, select only the empty cells. To do that, use Control-G, then click Special, select Blanks, and click OK.

At this point, only empty cells are selected, and I just need to add a formula to pull in the missing values. You might think you need something fancy but actually, due to the relative nature of references in Excel, the formula we need is dead simple. The key is starting with the right reference.

To do that, make sure the active cell in the selection is one of the empty cells.  The active cell will be the basis for all formulas we enter.

Next, enter a formula that sets the active cell to the address of the cell above it.

Now, instead of pressing Return, which would enter the formula in the active cell only, press Control + Return.

Control + Return enters the same formula into all selected cells at once. Because the formula contains a relative reference, Excel will update the address at each location. In effect, we're telling Excel to use "the cell above" to fill in all blank cells. This creates a chain of formulas that all "look up" to retrieve values.

Finally, we need to get rid of the formulas, so they don't cause problems if we sort or otherwise manipulate the data later. With all formulas selected, copy to the clipboard, then use Paste Special, and select values. This replaces all formulas with actual values.

Now we have a complete set of data that we can easily analyze.