Working with Special Features
The larger your worksheet grows, the longer it takes to recalculate the formulas in it. If you have a lot of changes to make, recalculating the worksheet at every change could take considerable time. You can speed things up by turning automatic recalculation off, recalculating the worksheet only when youíre ready. Here's how:
Select Options from the Tools menu.
Click the Calculation tab.
Under Calculation, select Manual.
Make sure Recalculate before save is checked.
Now, when you enter or edit data, Excel will not recalculate your formulas. Press F9 when youíre ready to recalculate.
Be aware that the recalculation setting affects all of your workbooks. When itís time to work with smaller workbooks, you might want to turn automatic recalculation back on.