Specify Calculation dialog box
This dialog box appears so that you can build a formula for a calculation or calculated field.
If necessary, for Evaluate this calculation from the context of, choose a table from the list.
Setting the context for a calculation is only necessary when you're creating a calculation field in a source table that has two or more occurrences in the relationships graph. The choice you make may affect the calculation results, particularly if your calculation will include fields in related tables.
For more information on the use of context in calculations, see Choosing the evaluation context for a calculation field.
In the calculation pane, click where you want the item to appear, then:
Choose a data type for Calculation result is <value>.
For Number of repetitions, type the number of repetitions. See Defining repeating fields.
Select Do not evaluate if all referenced fields are empty.
Important  To avoid confusion when using dates in FileMaker Pro, always define calculation formulas to enter four-digit years. See Conversion of dates with two-digit years.
To select indexing and storage options for the field, click Storage Options, choose options in the Storage Options dialog box, then click OK.
See Defining field indexing options and Defining global fields (fields with global storage).
If you are using FileMaker Pro Advanced to customize menus, you can base a menu or menu item title on the result of a calculation. You can also create tooltips based on a calculation. See Defining custom menus (FileMaker Pro Advanced) and Adding tooltips on layouts.
Related topics 
About functions
About formulas
Adding a new line to the results of a formula
Adding comments to a formula
Changing calculation formulas
Defining calculation fields
Defining automatic data entry
Defining field validation
Defining field indexing options