DAX RETURN

In DAX, when you use VAR to define one or more variables, you must use RETURN to tell DAX what to do with those variables i.e., what value to output from the measure or calculated column.

Syntax

Measure = 
VAR <Variable1> = <Expression1>
VAR <Variable2> = <Expression2>
RETURN
    <Final Expression using variables>

• VAR defines one or more variables.
• RETURN outputs the result of a final expression, typically using the variables you defined.

Why RETURN Is Essential

• Controls output: You must explicitly tell DAX what to return.
• Improves clarity: Helps structure your logic clearly first compute, then return.
• Supports debugging: You can temporarily return just one variable to inspect its value.

Optimization Example

• Without variables:

Profit Margin % =
DIVIDE(
    SUM(Sales[Profit]),
    SUM(Sales[Revenue]),
    0
) * 100

• With VAR and RETURN:

Profit Margin % =
VAR TotalProfit = SUM(Sales[Profit])
VAR TotalRevenue = SUM(Sales[Revenue])
RETURN
    DIVIDE(TotalProfit, TotalRevenue, 0) * 100

Why this is better?

• SUM(Sales[Revenue]) is only calculated once, not multiple times.
• The logic is clearer and easier to debug or edit later.

Example: Debugging with RETURN

You can return just a variable to test intermediate logic:

RETURN TotalRevenue

This is useful for step-by-step validation.

Advanced Example with Logic

VAR TotalSales = SUM(Sales[Amount])
VAR SalesTarget = 100000
RETURN
    IF(TotalSales >= SalesTarget, "Target Met", "Target Not Met")

Here, RETURN uses both variables to return a text result based on logic.

How RETURN Helps Optimize Variables