Calculated Columns and Measures in DAX

One of the first concepts to learn in DAX is the difference between calculated columns and measures. This article shortly recap the differences and describes when to use each one. Calculated columns When you create a data model in Power Pivot for Excel, Analysis Services Tabular, or Power BI Desktop, you can extend a table by creating new columns, which content is defined by a DAX expression evaluated row by row. The user interface is different depending on the tools you use. Excel and Analysis Services requires you to write the expression in the formula textbox when you select the last column on the right, which name is "Add Column". You can rename such a column name before or after you define the expression, right-clicking the new column and selecting the Rename Column menu item. As you see in the following picture, the DAX formula you write does not contain the column name and starts with the assignment symbol (=).