The Excel SKEW.P Function

Related Function:
SKEW Function
Skewness

The Skew of a population is a measurement of the asymmetry of the distribution about the mean.

  • A skew of zero indicates perfect symmetry;
  • A positive skew indicates that more values lie below the mean;
  • A negative skew indicates that more values lie above the mean.
Examples of Positive and Negative Skewed Distributions
Positive SkewNegative Skew
For more information on skewness, see the Wikipedia Skewness page

Basic Description

The Excel SKEW.P function calculates the skewness of the distribution of a supplied set of values.

Note: the Skew.P function was only introduced in Excel 2013 and so is not available in earlier versions of Excel.

The format of the function is:

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

Where the number arguments provide a minimum of 3 values that make up the data set. These can be individual numbers or arrays of numbers.


Skew.P Function Example

 AB
11 
21 
32 
42 
52 
62 
73 
83 
93 
104 
114 
125 
136 
147 
158 

Column A of the above spreadsheet on the right shows 15 data values. The distribution of these values is shown in the chart below:

Distribution of Points in Skew Function Example

The population skewness of the values in the spreadsheet can be calculated using the Excel Skew.P Function as follows:

=SKEW.P( A1:A15 )

This gives the result 0.774523929, which indicates that the data set has a positive skew.


Further details and examples of the Excel Skew.P function are provided on the Microsoft Office website.


Skew.P Function Errors

If you get an error from the Excel Skew.P function this is likely to be one of the following:

Common Errors
#DIV/0!-

Occurs if either:

  • Fewer than 3 data values have been supplied to the function;
  • The standard deviation of the data points is zero.
#VALUE!-

Occurs if any of the supplied number arguments that are supplied directly to the function are not recognised as numeric values.

(Note that if the Skew.P function is provided with a reference to a range of cells, any text values within this cell range are simply ignored and do not cause the function to return an error).