# Using functions in Excel

Creating formulas to perform complex mathematical calculations in Excel can be tricky and time-consuming, so you may prefer to use a function instead. A function is a preset formula that performs a calculation using specific values in a certain order. One of the most commonly-used function is SUM, which is used to add together the data in selected cells.

Excel comes with a large library of ready-to-use functions, which can be found in the Function Library on the Formulas tab. Here you can search for a wide range of functions that are grouped in categories such as Financial, Text, Date & Time and more.

#### How to use an Excel function

Like a formula, a function has to written correctly in order for Excel to complete the calculation. First you must begin with an equal sign (=), then the function name (for example SUM, which adds up numbers in selected cells), and then an argument - this is the information you want the function to calculate, for example a range of cell references.

Arguments must be enclosed in parentheses (brackets), with individual values or cell references inside the parentheses separated by either colons or commas:

• Colons refer to a range of cells so, for example, =AVERAGE(B2:B15) calculates the average of the cells from B2 through to B15.
• Commas separate individual values, cell references, and cell ranges in the parentheses. If you use more than one argument in your function, each one must be separated by a comma. For example, =COUNT(C1:C15,C17:C24,C38) will count all the cell values in the three cell ranges.

#### Write a basic Excel function

Step 1  Select the cell where you want the resulting calculation to appear.

Step 2  Type the equal sign (=) and then the function name.

Step 3  Enter the cell references for the argument inside the parenthesis.

Step 4  Press Enter. Excel will complete the calculation and present the answer in the selected cell.