Frequently Asked Questions

A calculated column is evaluated when the data is refreshed, and its values are stored in the model. A measure is evaluated while you work with the report and responds to the current filters, such as the selected region or period. Dynamic indicators usually call for measures, while calculated columns are needed for row-level calculations.

A confident command of the basic set is enough: CALCULATE (changing the filter context), SUM and SUMX (aggregation), DIVIDE (safe division) and the time intelligence functions — SAMEPERIODLASTYEAR, DATESYTD, TOTALYTD.

CALCULATE evaluates an expression after the filter conditions have been changed. It lets you calculate the sales of a specific category, for example, by replacing the current filter with the product category while keeping the other report filters in place. That is why understanding CALCULATE is required to build many of the more complex DAX formulas.

DAX for beginners is best started with the basic aggregation functions SUM, AVERAGE and COUNT, then DIVIDE and CALCULATE, and after that the time intelligence functions. Classic period-based calculations also require a separate date table that is created and configured correctly.

Copilot in Power BI is Microsoft's AI assistant that creates and edits reports, generates summaries, answers questions about your data and helps with DAX. The quality of the output depends on the Power BI semantic model.

The user describes the result they need in plain text, and Copilot for report creation picks the relevant data and builds a page with visuals. The result can be edited manually or refined with follow-up prompts.

Copilot in Microsoft Fabric helps generate and explain code, build queries, work with data processing pipelines, analyse information and prepare reports. As of 2026, some of these capabilities are still in preview.

No. Copilot automates part of the routine work, but the analyst still defines the business logic, builds the data model and verifies calculations and conclusions.

Microsoft Copilot Power BI depends on the quality of the model and the data, and it can return inaccurate answers. Critical calculations need to be verified, and at scale you also have to account for Fabric capacity consumption.

Yes. Standard use of Copilot requires a paid Microsoft Fabric capacity from F2 or a Power BI Premium capacity from P1, plus approval from your administrator. Microsoft also offers a separate Fabric Copilot capacity, so it is worth checking the licensing model for your own infrastructure before switching it on.