Remove Duplicates from a Selection of Data

SUMMARY: Quickly clear duplicated information from an Excel 2010 worksheet.

Depending on how data is entered or obtained from an external source, it is quite possible that rows with duplicate, or mostly duplicate, data could appear in your Microsoft Excel 2010 worksheet. While manually removing duplicate rows in a small worksheet is not much trouble, doing so in a 30,000 row worksheet would take a great deal of time and be prone to errors.

To solve the problem, Excel 2010 has a tool that can squash duplicate data with just a few mouse clicks. To do so:

1. Select the data that may contain duplicates.
2. Click the “Data” tab in the Ribbon.
3. Click “Remove Duplicates” in the “Data Tools” section.
Activating the “Remove Duplicates” function in Excel 2010

4. The “Remove Duplicates” dialog box appears. From here, check or uncheck boxes related to columns that you wish to use to check for duplicates. In the example worksheet shown, we want to remove duplicate rows where the student names match, not the grade numbers (several students may have the same grade, which is Ok in this example). Note you can use the “Select All” or “Unselect All” buttons to help manage these check boxes.

Using the “Remove Duplicates” tool in Excel 2010

5. Click “OK” to close the “Remove Duplicates” dialog box.

6. Excel 2010 will display a dialog box showing how many duplicates were found and how many remain. Click “OK” once you have read the information.