In DAX, which function is used to create a calculated measure?

In DAX, the appropriate function for creating a calculated measure is the CALCULATE function. This function plays a critical role in modifying the context in which a data calculation is performed. Specifically, CALCULATE allows users to change the filter context, providing the ability to specify particular filters that should be applied when calculating the measure.

While the SUM function is frequently used to aggregate values, it does not inherently create a calculated measure on its own; instead, it simply adds up numbers. The DEFINE statement, while useful in certain contexts, is not part of the standard DAX functions and is used in scenarios like creating measures in tools such as Tabular Models, but not in Power BI directly. The FILTER function serves to narrow down data based on specified criteria, and while it can be used within a measure, it does not create one by itself. Thus, the CALCULATE function stands out as the essential tool for constructing calculated measures in DAX, allowing for advanced data analysis and insights within Power BI.