Understanding Measure Calculation

Understanding Measure Calculation

Understanding how the DAX engine calculates measure results

When to use

When you need to clarify why a value is being returned as it is, or when you need to debug a result

Instructions

Key concepts around measure calculation:

• Every measure result is evaluated independently
• Each measure starts with the raw and unfiltered data tables
• Filters are applied to the underlying tables based on the “Filter Context”, reducing the number of rows to use in the calculation
• The Measure’s arithmetic signature is applied to whatever rows are left

What contributes to Filter Context?

• The intersection of any fields used in the current visual (each data point is a cross-section that inherits the rows/columns/axis/legend, etc.)
• Any selected data points in other visuals
• Selections made in any (all) slicers
• Page or report-level filter selections

Hints & tips

• If the measure contains a CALCULATE() function, this debugging chart will not be sufficient for your needs.  Please see the module on Understanding CALCULATE()