Manually Recalculate Formulas in PowerPivot
This topic describes how to temporarily change the settings of a PowerPivot workbook so that the results of formulas are no longer updated automatically. We recommend that you use the Automatic option whenever possible; however, manual recalculation of formulas might be necessary to mitigate the impact on workbook performance while you are designing formulas.
After you change this setting, you must manually trigger an update of any calculations that are based on formulas.
Before you publish the workbook you should always change the calculation mode back to automatic. This will help prevent problems when designing formulas.
Recalculating means updating the results of any formulas that use changed data. You need to recalculate whenever the formula changes, or when data that affects the results of calculations has changed or when the data has been refreshed. For more information about data refresh, see Different Ways to Update Data in PowerPivot.
In Windows Vista and Windows 7, features in the PowerPivot window are available on a ribbon, which is discussed in this topic. In Windows XP, features are available from a set of menus. If you are using Windows XP and want to see how the menu commands relate to the ribbon commands, see The PowerPivot UI in Windows XP.
To configure the workbook for manual recalculation
In the PowerPivot window, click the Design tab, and in the Calculations group, click Calculation Options.
Click Manual Calculation Mode.
To recalculate all tables, click Calculation Options again, and then click Calculate Now.
Formulas in the workbook are checked for errors, and tables are updated with results, if any. Depending on the amount of data and the number of calculations, the workbook may become unresponsive for some time.