Excel may appear to endlessly loop calculating cells when you insert several subtotals in a workbook

SYMPTOMS

When you insert several subtotals in a Microsoft Excel workbook, Excel may appear to endlessly loop calculating cells.

This behavior may occur because Excel recalculates once for each subtotal that is inserted in a workbook.

To work around this behavior, follow these steps, as appropriate for the version of Excel that you are running.

Click the Formulas tab.
Click Calculation Options in the Calculation group, and then click Manual.
Select the cell in which you want the subtotal to appear.
Click Math & Trig in the Function Library group, and then click SUBTOTAL.
In the Function Arguments dialog box, make the changes that you want, and then click OK.
After you have inserted all the subtotals that you want into the workbook, click Calculation Options in the Calculation group, and then click Automatic.

On the Tools menu, click Options.
On the Calculation tab, click Manual.
Click OK.
Select the cell in which you want the subtotal to appear.
On the Data menu, click Subtotals.
In the Subtotal dialog box, make the changes that you want, and then click OK.
After you have inserted all the subtotals that you want into your workbook, click Options on the Tools menu.
On the Calculation tab, click Automatic.
Click OK.