# Calculation Options

Calculation options determine how you wish Excel to perform calculation within
your workbooks, such as automatically recalculate workbooks when new data is
entered. If your workbook is VERY large, you may wish to change the calculation
option to manual so that Excel only recalculates your formulas when you ask
it to (by pressing the **F9** function key).

## Setting Calculation Method

- Display the Home ribbon and click on the
**Calculation Options** button within the Calculations area (at the right):
- Select one of the following options:

## Recalculating (if using Manual Calculation)

- Display the Home ribbon and click on one
of the following buttons within the Calculations area (at the right):

**Calculate Now** - to calculate the entire workbook.
**Calculate Sheet** - to calculate on the selected worksheet.

## Additional References