# Formula

The term "formula" has several different meanings, depending on the field in which the term is used. For example, a mathematical formula is a relationship expressed using numbers and symbols. A chemical formula defines the atomic structure of a chemical compound. In computing, a formula is a calculation performed on one or more variables.

### Formulas and Functions

Functions in computer programs often contain formulas. A simple formula, for instance, might convert centimeters to inches. This formula, along with several others, may be used within a metric conversion function. The function can apply the appropriate formula to the input (typically defined by the input parameters) and produce the resulting value as output. Formulas and functions are similar and sometimes the terms are used interchangeably. However, formulas are often the building blocks of functions, not the other way around.

### Spreadsheet Formulas

Formulas are also used in spreadsheets. Most spreadsheet applications allow you to enter formulas into cells instead of static data. For example, if a spreadsheet contains numbers in columns A and B, column C could be used to total the numbers in the respective rows of columns A and B. Entering the formula "=A2+B2" in cell C2 would display the sum of the cells A2 and B2 in C2. Advanced spreadsheet formulas can be used to determine the average of multiple cells, divide cells by the results of other formulas, and perform other complex operations.

**NOTE:** To enter a formula in a spreadsheet, start by typing an equal sign (=) into an empty cell.