# About formulas

Formulas perform specific operations on one or more values in a database file, and return a single result.

Formulas can be used to define:

•a calculation field. See Defining calculation fields.

•a calculated value for an automatic entry into a field. See Defining automatic data entry.

•a calculation that evaluates to true or false for data validation. See Defining field validation.

•a calculated value that can be used to replace the values in a field (by using the Replace Field Contents command in the Records menu or a script step). See Replacing the contents of a field.

•calculations in some FileMaker script steps, such as the script steps `If, Exit Loop If, Set Field, Insert Calculated Result`

, and `Replace Field Contents`

. See Automating tasks with scripts.

Formulas can contain:

•constants - numbers, text, date, or time values that don’t change.

•operators - symbols that indicate how to combine or compare two or more values.

•functions - predefined, named formulas that perform specific calculations and return single, specific values for each repetition.

•field references - fields in the same table or in a related table. A related field referenced in a calculation has the syntax `tablename::related`

field. See Working with related tables.

If a formula can’t be evaluated, it returns "?". To get an error code that indicates the cause of the problem, enclose the formula with the EvaluationError function.

## Examples

Formulas can be used in many places throughout FileMaker Pro Advanced. Here are some examples:

•Returns the first and last name separated by a space:

`FirstName & " " & LastName`

For example, Michelle Cannon.

•Returns the value in the SubTotal field multiplied by .08:

`SubTotal * .08`

•Returns the first and last name, each on a separate line:

`Field1 & ¶ & Field2`

For example,

Fred

Jane

About functions

Functions reference (category list)

Functions reference (alphabetical list)

Using operators in formulas

Identifying text constants and special characters in formulas

Adding comments to a formula

Using a reserved word or symbol for a field or table name