Most important 50 DAX functions

Here’s a curated list of the 50 most important DAX functions — grouped by category — that every Power BI Developer should know for interviews, certifications, and real-world use.

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📅 Date & Time Functions

1. TODAY() – Returns current date.
2. NOW() – Returns current date and time.
3. DATE() – Combines year, month, and day into a date.
4. DATEDIFF() – Calculates difference between two dates.
5. YEAR() – Extracts year from a date.
6. MONTH() – Extracts month from a date.
7. DAY() – Extracts day from a date.
8. WEEKNUM() – Returns week number of the year.
9. EOMONTH() – Returns end of month.
10. DATEADD() – Shifts date by interval (e.g., -1 year).

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⏳ Time Intelligence Functions

11. TOTALYTD() – Year-to-date total.
12. TOTALMTD() – Month-to-date total.
13. TOTALQTD() – Quarter-to-date total.
14. SAMEPERIODLASTYEAR() – Returns same period in prior year.
15. PREVIOUSMONTH() – Gets previous month’s dates.
16. NEXTMONTH() – Gets next month’s dates.
17. DATESYTD() – Returns YTD date range.
18. PARALLELPERIOD() – Gets a parallel period (e.g., same quarter last year).
19. FIRSTDATE() – First date in a column.
20. LASTDATE() – Last date in a column.

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🔢 Math & Aggregation Functions

21. SUM() – Sum of a column.
22. AVERAGE() – Average of a column.
23. MAX() – Maximum value.
24. MIN() – Minimum value.
25. COUNT() – Count of non-blank values.
26. COUNTA() – Count of all non-empty values.
27. COUNTROWS() – Count of rows in a table.
28. DIVIDE() – Safe division (avoids division by zero).
29. ROUND() – Round to decimal places.
30. RANKX() – Rank values based on expression.

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🧠 Logical & Conditional Functions

31. IF() – Basic condition logic.
32. SWITCH() – Advanced conditional logic.
33. AND() – Returns TRUE if all are TRUE.
34. OR() – Returns TRUE if any is TRUE.
35. NOT() – Reverses a logical value.

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📊 Filter Functions

36. CALCULATE() – Changes context of calculation.
37. FILTER() – Returns filtered table.
38. ALL() – Removes filters.
39. ALLEXCEPT() – Removes filters except specified columns.
40. REMOVEFILTERS() – Removes filters on one or more columns.

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🔗 Relationship & Table Functions

41. RELATED() – Returns a related value from another table.
42. RELATEDTABLE() – Returns a related table.
43. USERELATIONSHIP() – Forces use of inactive relationship.
44. VALUES() – Returns unique values in a column.
45. SELECTCOLUMNS() – Select specific columns from a table.
46. ADDCOLUMNS() – Adds calculated column to table.
47. SUMMARIZE() – Group by and aggregate.
48. CROSSJOIN() – Cartesian product of tables.

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🔤 Text Functions

49. CONCATENATE() / CONCATENATEX() – Joins strings (the X version aggregates across rows).
50. FORMAT() – Formats values (e.g., numbers, dates) into text.

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