Row Context & Filter Context: Evaluation Context in DAX

Posted by

September 21, 2026

On April 1, 2026

Introduction

When working with DAX, there is a core concept of evaluation context. Understanding this concept is crucial because it determines how the formulas in DAX return results. In other words, the evaluation context is an “environment” in which the formula is calculated. There are two types of evaluation context, row context, and filter context, which are completely different from each other.

Let’s break them down.

Learn about DAX in our blog: DAX in Power BI: As a formula language

What is the Evaluation Context in DAX

In layman’s terms, an evaluation context defines what data a DAX formula ‘sees’ or uses when it calculates a value. There are two types of evaluation context in DAX:

Row Context
Filter Context

Learn more about the evaluation context in our blog: The Rules of Evaluation

Row Context

When you write an expression in a calculated column, Power BI evaluates the expression for each row of the table and creates a row context for every row. In a similar manner, when you use an iterator like FILTER(), SUMX(), AVERAGEX(), ADDCOLUMNS(), or any one of the DAX functions that iterates over a table or a table expression, it creates a row context.

Learn more about basic iterators in our blog: Basic Iterators in DAX: AVERAGEX(), MINX() & MAXX()

A row context is created when any DAX expression is evaluated for each row. Row context can be created by:

Row context using Calculated Column:

When you create a calculated column, Power BI evaluates the expression for each row to generate the values in the new column. This creates a row context. Therefore, any function used for creating a calculated column in Power BI creates a row context.

Row context using Calculated Measure:

Measures may or may not create a row context. If the measure is created using an iterator function, then the expression is evaluated for each row, and therefore, a row context is created. Whereas, if the measures use regular functions, then no row context is created.

Filter Context

Filter context is evaluated based on the filtering applied to the data model in DAX. The Initial/Incoming filter context comes from:

Slicers
Data Fields of a visual (e.g. Rows and Columns in Matrix)
Page or Report Filters
From other visuals

Filter context can be modified or replaced by using the CALCULATE() function. Filters otherwise automatically follow relationships from 1 to many sides. Filters naturally flow from the 1 to many side to the many side in a relationship, so that totals and calculations stay accurate and consistent across the model. That’s also why excessive cross-filtering or bi-directional relationships are usually avoided, since they can create confusion, ambiguity, and unexpected results in reports.

Filter Context vs Row Context

There are always two contexts in DAX, and these are known as the pillars of DAX. Let’s look at some basic differences between these two:

	Filter Context	Row Context
Context Creation	Provided by the coordinates of the visual	Exists in Calculated Column or iterative DAX functions
Role of CALCULATE()	CALCULATE() function can be used to alter a filter context.	CALCULATE() can convert a row context to a filter context.
Relationships	Automatically follow the relationships from the 1 to many side.	Does not follow relationships or create a filter context.

Conclusion

In DAX, to create dynamic and precise calculations, it is crucial to comprehend row context and filter context. While filter context chooses which subset of data is considered based on filters from visuals, slicers, or DAX functions like CALCULATE(), row context enables formulas to evaluate one row at a time.

Writing effective DAX formulas, creating intelligent Power BI reports, and making sure your measurements consistently yield the desired outcomes all depend on your ability to master these two evaluation contexts.

FAQs

What is a row context in DAX

In row context, a DAX formula is evaluated one row at a time, as in calculated columns or when using iterator functions like SUMX() or FILTER(). Formulas can use other columns in the same row without aggregation.

What is filter context in DAX

The filter context determines which rows of data are taken into account when evaluating a DAX formula. Visuals, slicers, page filters, report filters, and the CALCULATE() function can all be used to alter it. For measures in Power BI, the filter context is crucial.

Why is understanding the evaluation context in DAX is important

Formulas can generate unexpected results if the row and filter context is not understood. You can create precise, dynamic DAX formulas that adjust to your reports by understanding how each context functions.

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