# Create a formula by using a function

** Important ** The calculated results of formulas and some Excel worksheet functions may differ slightly between a Windows PC using x86 or x86-64 architecture and a Windows RT PC using ARM architecture. Learn more about the differences.

You can create a formula (formula: A sequence of values, cell references, names, functions, or operators in a cell that together produce a new value. A formula always begins with an equal sign (=).) to calculate values in your worksheet by using a function (function: A prewritten formula that takes a value or values, performs an operation, and returns a value or values. Use functions to simplify and shorten formulas on a worksheet, especially those that perform lengthy or complex calculations.). For example, the formulas **=****SUM(****A1:A2)** and **SUM(A1,A2)** both use the **SUM** function to add the values in cells A1 and A2. Formulas always start with an equal sign (**=**).

- Click the cell in which you want to enter the formula.
- To start the formula with the function, click
**Insert Function**on the formula bar .

Excel inserts the equal sign (**=**) for you.

- In the
**Or select a category**box, select**All**.

If you are familiar with the function categories, you can also select a category.

If you're not sure which function to use, you can type a question that describes what you want to do in the **Search for a function** box (for example, "add numbers" returns the **SUM** function).

** Tip ** For a list of available functions, see Excel functions (alphabetical) or Excel functions (by category).

- In the
**Select a function**box, select the function that you want to use, and then click**OK**. - In the argument boxes that are displayed for the function you selected, enter the values, text strings, or cell references you want.

Instead of typing cell references, you can also select the cells that you want to reference. Click to minimize the dialog box, select the cells you want to reference, and then click to expand the dialog box again.

** Tip ** For more information about the function and its arguments, click **Help on this function**.

- After you complete the arguments for the formula, click
**OK**.

** Tip ** If you frequently use functions, you can enter your formulas directly on the worksheet. After you type the equal sign (=) and the function name, you can get information about the formula syntax and the function arguments by pressing F1.

### Examples

Use the embedded workbook shown here to work with examples of formulas that use a function. You can inspect and change formulas, and enter your own formulas.

To work in-depth with this workbook, you can download it to your computer and open it in Excel. For more information, see the article Download an embedded workbook from OneDrive and open it on your computer.