Practical Powerpivot & Dax Formulas For Excel -

CALCULATE : The most powerful function, used to modify the filter context of a calculation.

SUMX : An "iterator" function that performs a calculation row-by-row before summing the results. Practical PowerPivot & DAX Formulas for Excel

If you're looking for the "power" in PowerPivot, these common DAX functions highlighted by expert resources like Microsoft Support and Analytics Vidhya are essential: CALCULATE : The most powerful function, used to