In really large Excel 2013 workbooks that contain many completed worksheets, you may want to switch to manual recalculation so that you can control when the formulas in the worksheet are calculated. You need this kind of control when you find that Excel’s recalculation of formulas each time you enter or change information in cells has slowed the program’s response to a crawl.

By holding off recalculations until you are ready to save or print the workbook, you find that you can work with Excel’s worksheets without interminable delays.

To put the workbook into manual recalculation mode, you select the Manual option on the Calculation Options’ button on the Formulas tab of the Ribbon (Alt+MXM). After switching to manual recalculation, Excel displays CALCULATE on the status bar whenever you make a change to the worksheet that somehow affects the current values of its formulas.

Whenever Excel is in Calculate mode, you need to bring the formulas up-to-date in your worksheets before saving the workbook (as you would do before you print its worksheets).

To recalculate the formulas in a workbook when calculation is manual, press F9 or Ctrl+= (equal sign) or select the Calculate Now button (the one with a picture of a calculator in the upper-right corner of the Calculation group) on the Formulas tab (Alt+MB).

Excel then recalculates the formulas in all the worksheets of your workbook. If you made changes to only the current worksheet and you don’t want to wait around for Excel to recalculate every other worksheet in the workbook, you can restrict the recalculation to the current worksheet. Press Shift+F9 or click the Calculate Sheet button on the Formulas tab (Alt+MJ).

If your worksheet contains data tables that perform different what-if scenarios, you can have Excel automatically recalculate all parts of the worksheet except for those data tables by clicking Automatic Except Data Tables on the Calculation Options button’s drop-down menu on the Formulas tab (Alt+MXE).

To return a workbook to fully automatic recalculation mode, click the Automatic option on the Calculation Options button’s drop-down menu on the Formulas tab (Alt+MXA).