How to Calculate Skewness in Excel

In this Excel tutorial lesson, you will learn what skewness is and how to calculate skewness in an Excel application.

Skewness is the statistic by which you define asymmetry in the distribution of the analyzed variable. With skewness, you'll see how the results of your variable shape around the average. If their distribution is similar to the normal distribution (skewness equals to 0) or whether you can deal with the distribution positively skewed (skewness > 0) or negatively skewed (skewness <0).

To find the skewness in Excel, please prepare some data tables.

Skewness data table

Calculate Skewness using SKEW function

Excel provides a SKEW function. Syntax is:

=SKEW(number1, [number2], ...)

In this example, the formula is: =SKEW(B2:B13)

Skewness formula

Skewness here is strongly above 0 (skewness > 0), which means that it is a right-sided asymmetry. The conclusion is that for many months, sales were significantly lower than the average sales.

Calculate Skewness using Data Analysis ToolPak Add-In

First, you need to make sure your Data Analysis Toolpak Add-In is installed. Here is the lesson on how to install Data Analysis Toolpak Add-In.

Go to Ribbon to the Data tab. Click the Data Analysis button.

skewness Data Analysis ribbon button

A new window appears. Choose Descriptive Statistics and click OK.

skewness descriptive statistics

Enter the proper parameters:

  • Input Range - range of your data ($B$1:$B$13 in my example).
  • Labels in first row - there are labels in my data table.
  • Output Range - choose where you want to get your skewness calculated (I chose the same Sheet $E$1:$F$15).
  • Summary statistics - make sure it is checked.

skewness decriptive statistics parameters

And this is how you see my statistics summary. Skewness is calculated in row 10. The result is the same as in Example 1 where we checked how to calculate Skewness using the SKEW Excel function.

skewness calculated

Excel really helps you with statistics. Maybe now you can see that.

Further reading: 
Statistical process control chart
Calculating forecast accuracy and precision
How to calculate Standard Deviation?