Functions

When using Excel functions play an important role in finding values for a range of cells. Learn all about using functions in Excel.

Introduction

Video: Functions

Launch "Functions" video!Watch the video (5:17).

A function is a predefined formula that performs calculations using specific values in a particular order. Excel includes many common functions that can be useful for quickly finding the sum, average, count, maximum value, and minimum value for a range of cells. In order to use functions correctly, you'll need to understand the different parts of a function and how to create arguments to calculate values and cell references.

Optional: Download our practice workbook.

The parts of a function

In order to work correctly, a function must be written a specific way, which is called the syntax. The basic syntax for a function is the equals sign (=), the function name (SUM, for example), and one or more arguments. Arguments contain the information you want to calculate. The function in the example below would add the values of the cell range A1:A20.

Screenshot of Excel 2013Syntax of a basic function

Working with arguments

Arguments can refer to both individual cells and cell ranges and must be enclosed within parentheses. You can include one argument or multiple arguments, depending on the syntax required for the function.

For example, the function =AVERAGE(B1:B9) would calculate the average of the values in the cell range B1:B9. This function contains only one argument.

Screenshot of Excel 2013A function with a single argument

Multiple arguments must be separated by a comma. For example, the function =SUM(A1:A3, C1:C2, E1) will add the values of all the cells in the three arguments.

Screenshot of Excel 2013A function with multiple arguments

Creating a function

Excel has a variety of functions available. Here are some of the most common functions you'll use:

To create a basic function:

In our example below, we'll create a basic function to calculate the average price per unit for a list of recently ordered items using the AVERAGE function.

  1. Select the cell that will contain the function. In our example, we'll select cell C11.
    Screenshot of Excel 2013Selecting cell C11
  2. Type the equals sign (=) and enter the desired function name. You can also select the desired function from the list of suggested functions that will appear below the cell as you type. In our example, we'll type =AVERAGE.


    Screenshot of Excel 2013Entering the AVERAGE function
  3. Enter the cell range for the argument inside parentheses. In our example, we'll type (C3:C10). This formula will add the values of cells C3:C10 and then divide that value by the total number of cells in the range to determine the average.


    Screenshot of Excel 2013Creating an argument
  4. Press Enter on your keyboard. The function will be calculated, and the result will appear in the cell. In our example, the average price per unit of items ordered was $15.93.


    Screenshot of Excel 2013The completed function and calculated value

Excel will not always tell you if your formula contains an error, so it's up to you to check all of your formulas. To learn how to do this, read the Double-Check Your Formulas lesson from our Excel Formulas tutorial.

To create a function using the AutoSum command:

The AutoSum command allows you to automatically insert the most common functions into your formula, including SUM, AVERAGE, COUNT, MIN, and MAX. In our example below, we'll create a function to calculate the total cost for a list of recently ordered items using the SUM function.

  1. Select the cell that will contain the function. In our example, we'll select cell D12.
    Screenshot of Excel 2013Selecting cell D12
  2. In the Editing group on the Home tab, locate and select the arrow next to the AutoSum command and then choose the desired function from the drop-down menu. In our example, we'll select Sum.


    Screenshot of Excel 2013Selecting Sum from the AutoSum command drop-down menu
  3. The selected function will appear in the cell. If logically placed, the AutoSum command will automatically select a cell range for the argument. In our example, cells D3:D11 were selected automatically and their values will be added together to calculate the total cost. You can also manually enter the desired cell range into the argument.
    Screenshot of Excel 2013The inserted function and automatically selected cell range
  4. Press Enter on your keyboard. The function will be calculated, and the result will appear in the cell. In our example, the sum of D3:D11 is $606.05.


    Screenshot of Excel 2013The completed function and calculated value

The AutoSum command can also be accessed from the Formulas tab on the Ribbon.

Screenshot of Excel 2013Accessing the AutoSum command from the Formulas tab

The Function Library

While there are hundreds of functions in Excel, the ones you use most frequently will depend on the type of data your workbooks contains. There is no need to learn every single function, but exploring some of the different types of functions will be helpful as you create new projects. You can search for functions by category, such as Financial, Logical, Text, Date & Time, and more from the Function Library on the Formulas tab.

Click the buttons in the interactive below to learn more about the different types of functions in Excel.

labeled graphic

Insert Function

If you're having trouble finding the right function, the Insert Function command allows you to search for functions using keywords.

AutoSum Command

The AutoSum command allows you to automatically return results for common functions, like SUM, AVERAGE, and COUNT.

Recently Used

The Recently Used command gives you access to functions you've recently worked with.

Financial

The Financial category contains functions for financial calculations like determining a payment (PMT) or interest rate for a loan (RATE).

Logical

Functions in the Logical category check arguments for a value or condition. For example, if an order is more than $50 add $4.99 for shipping, but if it is more than $100 do not charge for shipping (IF).

Text

The Text category contains functions that work with the text in arguments to perform tasks, such as converting text to lowercase (LOWER) or replacing text (REPLACE).

Date & Time

The Date & Time category contains functions for working with dates and time and will return results like the current date and time (NOW) or the seconds (SECOND).

Lookup & Reference

The Lookup & Reference category contains functions that will return results for finding and referencing information. For example, you can add a hyperlink (HYPERLINK) to a cell or return the value of a particular row and column intersection (INDEX).

Math & Trig

The Math & Trig category includes functions for numerical arguments. For example, you can round values (ROUND), find the value of Pi (PI) multiply (PRODUCT), and subtotal (SUBTOTAL).

More Functions

More Functions contains additional functions under categories for Statistical, Engineering, Cube, Information, and Compatibility.

To insert a function from the Function Library:

In our example below, we'll use a function to calculate the number of business days it took to receive items after they were ordered. In our example, we'll use the dates in columns B and C to calculate the delivery time in column D.

  1. Select the cell that will contain the function. In our example, we'll select cell D3.
    Screenshot of Excel 2013Selecting cell D3
  2. Click the Formulas tab on the Ribbon to access the Function Library.
  3. From the Function Library group, select the desired function category. In our example, we'll choose Date & Time.
    Screenshot of Excel 2013Selecting the Date & Time category from the Function Library
  4. Select the desired function from the drop-down menu. In our example, we'll select the NETWORKDAYS function to count the number of business days between the ordered date and received date.
    Screenshot of Excel 2013Selecting the NETWORKDAYS function
  5. The Function Arguments dialog box will appear. From here, you'll be able to enter or select the cells that will make up the arguments in the function. In our example, we'll enter B3 in the Start_date: field and C3 in the End_date: field.
  6. When you're satisfied with the arguments, click OK.
    Screenshot of Excel 2013Clicking OK
  7. The function will be calculated, and the result will appear in the cell. In our example, the result shows that it took four business days to receive the order.
    Screenshot of Excel 2013The completed function and calculated value

Like formulas, functions can be copied to adjacent cells. Hover the mouse over the cell that contains the function, then click, hold, and drag the fill handle over the cells you want to fill. The function will be copied, and values for those cells will be calculated relative to their rows or columns.

Screenshot of Excel 2013Copying a function to adjacent cells using the fill handle

The Insert Function command

If you're having trouble finding the right function, the Insert Function command allows you to search for functions using keywords. While it can be useful, this command is sometimes difficult to use. If you don't have much experience with functions, you may have more success browsing the Function Library instead. For more advanced users, however, the Insert Function command can be a powerful way to find a function quickly.

To use the Insert Function command:

In our example below, we want to find a function that will count the total number of items ordered. We want to count the cells in the Item column, which uses text. We cannot use the basic COUNT function because it will only count cells with numerical information. Instead, we will need to find a function that counts the total number of cells within a cell range.

  1. Select the cell that will contain the function. In our example, we'll select cell B16.
    Screenshot of Excel 2013Selecting cell B16
  2. Click the Formulas tab on the Ribbon, then select the Insert Function command.
    Screenshot of Excel 2013Selecting the Insert Function command
  3. The Insert Function dialog box will appear.
  4. Type a few keywords describing the calculation you want the function to perform, then click Go. In our example, we'll type Count cells, but you can also search by selecting a category from the drop-down list.
    Screenshot of Excel 2013Searching for a function with keywords
  5. Review the results to find the desired function, then click OK. In our example, we'll choose COUNTA because it will count the number of cells in a cell range.
    Screenshot of Excel 2013Selecting a function and clicking OK
  6. The Function Arguments dialog box will appear. Select the Value1: field, then enter or select the desired cells. In our example, we'll enter the cell range A3:A10. You may continue to add arguments in the Value2: field, but in this case we only want to count the number of cells in the cell range A3:A10.
  7. When you're satisfied, click OK.


    Screenshot of Excel 2013Entering an argument and clicking OK
  8. The function will be calculated, and the result will appear in the cell. In our example, the result shows that a total of eight items were ordered.
    Screenshot of Excel 2013The completed function and calculated value

If you're comfortable with basic functions, you may want to try a more advanced one like VLOOKUP. You can check out our article on How to Use Excel's VLOOKUP Function for more information. If you want to learn even more about functions, check out our Excel Formulas tutorial.

Challenge!

  1. Open an existing Excel workbook. If you want, you can use our practice workbook.
  2. Create a function that contains one argument. If you're using the example, use the SUM function in cell B16 to calculate the total quantity of items ordered.
  3. Use the AutoSum command to insert a function. If you are using the example, insert the MAX function in cell B23 and use the cell range D3:D15 for the argument to find the most expensive item that was ordered.
  4. Explore the Function Library, and try using the Insert Function command to search for different types of functions.