XL97: File Size Increases When You Save the File in 97 Format (162173)

CAUSE

There are two main factors that affect how drastically the file size changes when you save it in the Microsoft Excel 97 workbook format. For these reasons, the file size of a workbook may increase slightly when you save it in the Microsoft Excel 97 workbook format. However, the increase in size is not substantial.

Case 1

When you save a workbook in Microsoft Excel, summary information is saved with the workbook. When you save a workbook in the Microsoft Excel 97 workbook format, the file size of the workbook increases because more summary information is saved with the workbook than when you save it in the Microsoft Excel 5.0 workbook format. Specifically, the file size increases if you save a preview picture with the workbook.

Usually, the file size of the workbook is increased by no more than 25 to 30 kilobytes (KB), regardless of the file size of the workbook.

NOTE: If you save the workbook with a zoom setting that is less than 100%, and you save a preview picture with the workbook, the amount by which the file size increases may be much larger. This is true because the preview picture is larger when the zoom setting is less than 100%.

Case 2

When you save a workbook in the Microsoft Excel 97 workbook format, the contents of the workbook is optimized. For example, if a worksheet contains a range of formulas that are very similar to each other, Microsoft Excel treats the formulas as "shared" formulas so that they occupy less disk space. In some cases, the decrease in file size is substantial.

For more information, please see the following article in the Microsoft Knowledge Base:

104310 Non-Excel 5.0 Documents Take a Long Time to Open and Save

Other Causes

For more information about why your workbooks may increase in size when saved in the Microsoft Excel 97 workbook format, please see the following article in the Microsoft Knowledge Base:

166092 File Size Increases After Launching Visual Basic Editor

WORKAROUND

To work around this behavior, use the following appropriate method.

Method 1: Remove the Preview Picture

To remove the preview picture, use the following steps:

Open the workbook in Microsoft Excel 97.
On the File menu, click Properties. Click the Summary tab.
Clear (uncheck) the Save Preview Picture check box and click OK.
On the File menu, click Save.

After you click Save, the file size of the workbook should decrease by up to 30 KB in size.

Method 2: Increase the Zoom Setting

If you must save the workbook with a preview picture, decrease the size of the workbook by changing the zoom setting to a value of 100% or greater. To do this, type the number in the Zoom box on the Standard toolbar.

MORE INFORMATION

The following table lists examples of how the file sizes of workbooks may change, depending on how you save the workbooks. Note that the file sizes are in bytes.

                                Size of     Size of     Size of

   Process                      Test1.xls   Test2.xls   Test3.xls
   --------------------------------------------------------------

   File is originally created      14,336     180,736      62,976
   in Microsoft Excel 5.0.

   File is opened in Microsoft     32,256     200,704      87,552
   Excel 97 and saved in the
   Microsoft Excel 97 format
   with a preview picture.

   File is opened in Microsoft     44,032     214,016     105,984
   Excel 97, zoom is set to 50%,
   and file is saved in the
   Microsoft Excel 97 format
   with a preview picture.

   File is opened in Microsoft     17,408     183,808      65,536
   Excel 97 and saved in the
   Microsoft Excel 97 format
   WITHOUT a preview picture.

The following notes contain more details about the examples in the table:

The file size for each workbook increases by 18 - 25 KB when you save the workbook in the Microsoft Excel 97 workbook format. This behavior is due primarily to the additional summary information and the preview picture that is saved with the workbook.
In each of the examples, when you remove the preview picture from the workbook, the net increase in the size of the workbook is roughly 3 KB.
If you remove the preview picture from each workbook by clearing the "Save preview picture" check box in the Properties dialog box, the size of each workbook decreases by 15 - 22 KB.
Setting the zoom setting for a workbook to a value that is less than 100%, and then saving a preview picture with the workbook may cause the workbook file size to increase substantially.

How Each Sample Workbook Is Created in Microsoft Excel 5.0

Test1.xls:

Create a new workbook with sixteen worksheets. In Sheet1, type a random value in cell A1. Save and close the workbook.

Test2.xls:

Create a new workbook with sixteen worksheets. In Sheet1, type random values in the cell range A1:A4096. Save and close the workbook.

Test3.xls:

Create a new workbook with sixteen worksheets. In Sheet1, type random values in the cell range A1:D512. Save and close the workbook.