To **standardize** a variable means to scale each of the values for the variable such that the mean value is 0 and the standard deviation is 1.

You can use the following formula to standardize a variable

**(x _{i} – x) / s**

where:

**x**: The i_{i}^{th}value in the dataset**x**: The sample mean**s**: The sample standard deviation

The easiest way to standardize a variable in SAS is to use the **PROC STDIZE** statement.

The following example shows how to use this statement in practice.

**Example: How to Use PROC STDIZE in SAS**

Suppose we have the following dataset in SAS that contains information about various basketball players:

**/*create first dataset*/
data my_data;
input player $ points assists rebounds;
datalines;
A 18 3 15
B 20 3 14
C 19 4 14
D 14 5 10
E 14 4 8
F 15 7 14
G 20 8 13
H 28 7 9
I 30 6 5
J 0 31 9 4
;
run;
/*view dataset*/
proc print data=my_data;
**

We can use the **PROC STDIZE** statement to create a new dataset that standardizes each of the numeric variables in the dataset:

**/*standardize all numeric variables in dataset*/
proc stdize data=my_data out=std_data;
run;
/*view new dataset*/
proc print data=std_data;**

Each of the numeric variables (points, assists, rebounds) have been standardized to have a mean of 0 and standard deviation of 1.

Note that we can also use the **VAR** statement to specify which variables to standardize.

For example, we can use the following **PROC STDIZE** statement with the **VAR** statement to only standardize the points variable:

**/*standardize points variable in dataset*/
proc stdize data=my_data out=std_data;
var points;
run;
/*view new dataset*/
proc print data=std_data;**

The values in the points column have been standardized while all other columns have remained untouched.

We can use the **PROC MEANS** statement to verify that the points variable now has a mean value of 0 and a standard deviation of 1:

/*view mean and standard deviation of each variable*/proc means data=std_data;

We can see that the points variable indeed has a mean value of 0 and a standard deviation of 1.

**Additional Resources**

The following tutorials explain how to perform other common tasks in SAS:

How to Remove Rows with Missing Values in SAS

How to Calculate Standard Deviation in SAS (3 Examples)

How to Calculate Z-Scores in SAS