Table of Contents### About Calculations, Formulas, and Functions

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Calculations, formulas, and functions are related concepts. These three terms have specific meanings that you need to understand to get started. Each will be described more fully throughout the hour.

Formulas are operations performed on data that can be stored in the database or entered as part of the formula. A formula can consist of one or more expressions; each expression yields a resulting value. Formulas frequently combine constants (values entered into the formula) and field references (contents of a specified field in the current record).

`2+2`is both an expression and a formula; it contains two constants.`2*mileage`is an expression and formula containing one constant and one field reference (assuming your table has a field named “mileage”).`(2+2)/(2*mileage)`is a single formula composed of two expressions.Functions are formulas that return a result from one or more arguments, which are placed in parentheses. For example,

`Sum(merchandise; salestax; shipping)`is a formula that computes the total for an invoice. FileMaker defines a number of built-in functions such as this one. Some take an unlimited number of parameters (such as`Sum`); others take specific parameters in a specific order (such as`Sqrt`, which takes a single number from which a square root is calculated and returned). Still other functions have no arguments—`Pi`returns the geometric constant, and`Random`returns a single random number. A function can be an expression, which in turn can be a formula or part of a formula.Calculation fields are database fields that contain formulas (and, by extension, expressions and functions).