If your data source doesn’t include the fields that you are looking for, then you can create a tableau Calculated Field. This article will show you how to create a calculated Field in Tableau with an example.
How to Create a Calculated Field in Tableau
You can create a Tableau calculated field in multiple ways. The first approach is: Please navigate to Analysis Tab and select the Create Calculated Field… option.
Once you click on the Create option, a new window will be opened to write the calculation.
Please click on the Down arrow beside the Sales Amount Measure (change as per your requirement). Or right-click on it to open the context menu. From the list of available options, please select the Create option and then select the Tableau Calculated Field… option as shown below.
Once you click on the option, a new window will be opened to write the calculation. Use this calculation editor to write functions.
If you know the calculated field formula, you can write directly on that Measure or any other Measure. Otherwise, click on the side arrow to list all the functions available.
If you know the function name, use the search box to search for the item. And, if you don’t know, click the down arrow, select the function type, and see the definition.
In this Tableau field example, we will calculate the Running Total, so we are using the RUNNING_SUM function. Here, you can see the example to understand the syntax of a function.
Double click on it will automatically add the function to the calculated region. From the below screenshot you can observe that we changed the name to Sales Running Sum.
Now you can see our newly created calculated field under measures
We created one table report to show our newly created calculated field result. As you can see, the last column displays the Running Total.
Edit Calculated Field in Tableau
To change the existing table calculation, click on the down arrow beside the table calculation, and select the Edit.. option.
Once you click the Edit.. option, the following window will be opened to edit the existing calculation or function.
Let us change the Tableau calculated field function name from RUNNING_SUM to RUNNING_AVG. Or write your custom function on the calculation editor and click OK
Now you can see that the last column in our report displays the Running Average calculation.