You may wish to save a workbook in a different format. For instance, if you know the workbook will be used on a computer with an earlier version of Excel, you should save the file in a file format compatible with that version. In this case, you must change the format of the document before you save it.
To save a workbook with a different format:
The most common file formats to save as are:
You can also use the Save As dialog box to save the workbook with a new name: