By default, Microsoft Excel automatically recalculates formulas when the cells that the formula depends on have changed.
Calculate a worksheet or workbook now
Press F9 Calculates formulas that have changed since the last calculation, and formulas dependent on them, in all open workbooks. If a workbook is set for automatic calculation, you do not need to press F9 for calculation.
Press SHIFT+F9 Calculates formulas that have changed since the last calculation, and formulas dependent on them, in the active worksheet.
Press CTRL+ALT+F9 Calculates all formulas in all open workbooks, regardless of whether they have changed since last time or not.
Press CTRL+SHIFT+ALT+F9 Rechecks dependent formulas, and then calculates all formulas in all open workbooks, regardless of whether they have changed since last time or not.
Change when a worksheet or workbook calculates
Changing this option affects all open workbooks.
To calculate only the active worksheet, press SHIFT+F9.
Note If a worksheet contains a formula that is linked to a worksheet that has not been calculated and you update that link, Excel displays a message stating that the source worksheet is not completely calculated. To update the link with the current value stored on the source worksheet, even though the value might not be correct, click OK. To cancel updating the link and use the previous value obtained from the source worksheet, click Cancel.
Change the precision of calculations in a workbook
Caution When you change the precision of the calculations in a workbook by using the displayed (formatted) values, Excel permanently changes any constant values on the worksheets in the workbook. If you later choose to calculate with full precision, the original underlying values cannot be restored.
Change the number of times Microsoft Excel iterates a formula