Working on a large database can often create confusions. It is not uncommon to create duplicate columns by mistake. Excel offers a great fix to diagnose if there are identical columns. We can do this by highlighting duplicate columns. We use the SUMPRODUCT function along with conditional formatting to do this. In this lesson, we will learn how to highlight duplicate columns in Excel.

*Figure 1. Example of How to Highlight Duplicate Columns in Excel*

**Formula**

**=SUMPRODUCT ((row1=reference1) * (row2=reference) * (row3=reference3)) >1**

This formula is based on the SUMPRODUCT function. It counts how many times each value occurs in the table, in a row wise manner. The function will provide TRUE if the values are same in all the rows.

We use absolute row references. But the cell references are mixed, where the row is locked. This checks all instances of the row for duplicates.

**Setting up Data**

The following database contains some sample text. Column A to D has these texts.

* Figure 2. The Data Set*

To highlight duplicate columns, we need to:

- Click on cell
**A2.**Drag the selection from cells**A2 to D6.** - In the
**home**tab of the ribbon, click**Conditional Formatting > New Rule**.

* Figure 3. Example of how to Apply Conditional Formatting*

- Select
**Use a formula to determine which cells to format**.

* Figure 4. Applying the Formula*

- Next, we need to assign the formula
This needs to be assigned in the`=SUMPRODUCT(($A$2:$D$2=A$2)*($A$3:$D$3=A$3)*($A$4:$D$4=A$4)*($A$5:$D$5=A$5))>1`

.**Format values where this formula is true**box, - Next, we need to click on
**Format**. - Select
**Fill>Background Color**and set it to the color of your choice.

* Figure 5. Formatting the Display*

- Click
**Ok**twice.

*Figure 6. The Final Result*

This will highlight the duplicate columns B and C using the conditional formatting.

Most of the time, the problem you will need to solve will be more complex than a simple application of a formula or function. If you want to save hours of research and frustration, try our live Excelchat service! Our Excel Experts are available 24/7 to answer any Excel question you may have. We guarantee a connection within 30 seconds and a customized solution within 20 minutes.

## Leave a Comment