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Optimize DAX with Variables

Use VAR statements in DAX to improve readability, debugging, and performance by calculating values only once.

Published 27 December 2025

The Power of VAR

VAR statements in DAX let you store intermediate calculations, making your code cleaner and often faster.

Before: Repeated Calculations

Profit Margin =
DIVIDE(
    SUM(Sales[Revenue]) - SUM(Sales[Cost]),
    SUM(Sales[Revenue])
) * 100

Here, SUM(Sales[Revenue]) is calculated twice.

After: Using Variables

Profit Margin =
VAR TotalRevenue = SUM(Sales[Revenue])
VAR TotalCost = SUM(Sales[Cost])
VAR Profit = TotalRevenue - TotalCost
RETURN
    DIVIDE(Profit, TotalRevenue) * 100

Benefits

Performance: Each calculation runs only once
Readability: Clear, self-documenting code
Debugging: Hover over variables to see values
Maintenance: Change logic in one place

Advanced Pattern: Conditional Logic

Sales Status =
VAR CurrentSales = [Total Sales]
VAR Target = [Sales Target]
VAR Achievement = DIVIDE(CurrentSales, Target)
RETURN
    SWITCH(
        TRUE(),
        Achievement >= 1, "Exceeded",
        Achievement >= 0.8, "On Track",
        Achievement >= 0.5, "At Risk",
        "Critical"
    )

Tip: Use descriptive variable names. Future you will thank present you.