How to Add Comments to Power BI DAX Codes

Updated on:

May 12, 2026

By:

Use this interactive demo to learn how to annotate DAX formulas with inline comments in Power BI.

Quick summary

Adding comments to Power BI DAX code helps analysts document their logic directly inside the data model formula bar, making measures easier to audit and maintain. You can comment out any DAX line instantly using a double-dash syntax without affecting report calculations.

Steps

Inside Power BI's data model, click the formula bar and type two dashes (--) on the line where you want to add a comment.
After typing the double dashes, type your comment text on the same line.
Click the Commit button to apply and save the changes to your DAX code.
After completing these steps, your comments are added to the DAX code in your Power BI report.

📌 Why this matters

Commenting DAX code in Power BI is a critical best practice for data teams who need to keep their measures readable, auditable, and easy to hand off. Using the double-dash (--) syntax, analysts can document complex calculation logic directly inside the formula bar without disrupting report output. This makes Power BI data models significantly easier to maintain, debug, and collaborate on across teams. Clear DAX documentation reduces onboarding time and prevents costly errors when formulas are revisited or modified.

Your product deserves an interactive demo

Start free

How to Uninstall Power BI

How to Compare Two Measures in Power BI

How to Compare Months in Power BI