Using Variables in DAX Queries and Measures

September 8, 2026 23 visits

In this article, we will learn how to use VAR and
RETURN in DAX to store intermediate calculations,
simplify formulas, and create a reusable sales tax measure.

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What Are Variables in DAX?

Variables in DAX allow you to store the result of an expression and
reuse it later in the same calculation. They make complex formulas
easier to read, understand, and maintain.

Variables are created using VAR and the final result
is returned using RETURN.

DAX Syntax
VAR VariableName = Expression
RETURN
    ResultExpression

Understanding VAR and RETURN

VAR: Creates a variable and stores the result of an
expression.

RETURN: Specifies the final expression whose result
will be returned.

Key takeaway:
Variables help you break a calculation into smaller, meaningful steps
instead of writing one long formula.

1. Using Variables in a DAX Query

Query

DAX Query
EVALUATE
    VAR TotalSalesAmount = SUM(Sales[Sales Amount])
    VAR TaxAmount = 18
    VAR TotalTaxAmount = TotalSalesAmount * (TaxAmount/100)
RETURN
    ROW(
        "Total Tax", TotalTaxAmount
    )

Step-by-step explanation

Step 1: EVALUATE
EVALUATE tells DAX to return the result of a table
expression. In this query, the final result is created using
ROW.

Step 2: VAR TotalSalesAmount
TotalSalesAmount stores the result of
SUM(Sales[Sales Amount]).

First Variable
VAR TotalSalesAmount = SUM(Sales[Sales Amount])

This calculates the total sales amount from the
Sales[Sales Amount] column.

Step 3: VAR TaxAmount
TaxAmount stores the value 18,
representing an 18% tax rate.

Second Variable
VAR TaxAmount = 18

Step 4: VAR TotalTaxAmount
This variable calculates the tax amount by multiplying the total sales
by the tax rate divided by 100.

Third Variable
VAR TotalTaxAmount = TotalSalesAmount * (TaxAmount/100)

The calculation is:

Tax Calculation
Total Tax = Total Sales × (18 / 100)

Step 5: RETURN
RETURN specifies the final expression that DAX should
evaluate and return.

Step 6: ROW
ROW creates a table containing one row and one column.
The output column is named Total Tax.

Final Result Expression
ROW(
    "Total Tax", TotalTaxAmount
)

What will you get?

The query returns a single-row table containing the calculated tax amount.

Total Tax
18% of Total Sales

The exact value depends on the total sales amount in your
Sales table.

Key takeaway:
The query uses three variables to calculate the tax and then returns
the result as a table using ROW.

2. Creating a Measure Using Variables

Measure

DAX Measure
Total Tax Amount = 
VAR TotalSalesAmount = SUM(Sales[Sales Amount])
VAR TaxAmount = 18
RETURN TotalSalesAmount * TaxAmount

Step-by-step explanation

Step 1: Measure name
Total Tax Amount is the name of the measure.

Step 2: VAR TotalSalesAmount
This variable calculates the total sales amount using
SUM(Sales[Sales Amount]).

Step 3: VAR TaxAmount
This variable stores the tax rate as 18.

Step 4: RETURN
The RETURN statement specifies the final calculation
that the measure should return.

Final Calculation
RETURN TotalSalesAmount * TaxAmount

Important: Correcting the Tax Calculation

The measure above multiplies the total sales amount by
18, not 18%.

To calculate an 18% tax amount, the tax rate must be divided by 100.
The corrected measure is:

Corrected DAX Measure
Total Tax Amount = 
VAR TotalSalesAmount = SUM(Sales[Sales Amount])
VAR TaxAmount = 18
RETURN TotalSalesAmount * (TaxAmount/100)

This ensures that the measure calculates 18% of Total Sales.

Key takeaway:
When a percentage is stored as a whole number such as 18,
divide it by 100 before multiplying it with the amount.

3. Understanding the Difference Between the Query and Measure

Feature DAX Query DAX Measure
Purpose Returns a result for a query Creates a reusable calculation
Uses VAR Yes Yes
Uses RETURN Yes Yes
Final result Table expression Scalar value
Example EVALUATE ROW(…) Total Tax Amount = …

4. Why Should You Use Variables?

1. Improved readability

Variables give meaningful names to intermediate calculations,
making the formula easier to understand.

2. Easier maintenance

If you need to change the tax rate, you can update the value of
TaxAmount in one place.

3. Reuse intermediate results

A variable can be used multiple times in the final calculation,
avoiding repeated expressions.

4. Simplifies complex calculations

Instead of writing a long formula, you can divide the calculation
into smaller steps using multiple variables.

📝 Practice Exercise

Try creating a DAX measure to calculate 10% Tax
on the total sales amount.

Use the following steps:

  1. Create a variable for total sales.
  2. Create a variable for the tax rate.
  3. Calculate the tax amount.
  4. Return the final result.

Expected Measure

DAX Measure
Total Tax Amount = 
VAR TotalSalesAmount = SUM(Sales[Sales Amount])
VAR TaxAmount = 10
RETURN TotalSalesAmount * (TaxAmount/100)

Conclusion

In this article, we learned how to use variables in DAX queries
and measures.

  • VAR creates a variable and stores an expression result.
  • RETURN specifies the final expression.
  • Variables make DAX formulas easier to read and maintain.
  • EVALUATE returns the result of a table expression.
  • ROW creates a single-row table for the query result.
  • Measures return a scalar value and can be reused in reports.
  • Percentage calculations should divide the rate by 100.

Variables are an essential part of writing clean and efficient DAX
calculations. Once you understand VAR and
RETURN, you can start building more advanced
business calculations with confidence.

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