Note, this article is being retired soon. The Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint file formats is no longer available for download.
If someone sends you an Excel 2013 workbook, but you have an earlier version of Excel, use the Compatibility Pack to open Excel 2013 workbooks (*.xlsx or *.xlsm) directly in your version of Excel without having to upgrade.
Download and install the Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats.
Open the Excel 2013 workbook in the earlier version of Excel.
The Compatibility Pack lets you edit the workbook, and you can save it to the earlier file format (*.xls or *.xlm).
Note: Excel 2013-specific features and formatting may not be shown in the earlier version of Excel, but they are still available when the workbook is saved in the earlier version and re-opened in Excel 2013.