⚡Power BI’s New User Defined Functions: 10 Must-Have You’ll Use in Every Report

Fast, consistent DAX — packaged once, reused forever.

By Isabelle Bittar for KI Data Science

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Introduction

Power BI recently introduced (in Preview) DAX User-Defined Functions (UDFs) — a way to package DAX logic once and call it anywhere, just like reusable helpers.

Why they matter

• ♻️ Reusability: Write once, reuse across visuals, pages, and PBIX files.
• 🧭 Consistency: One source of truth for logic (time intelligence, colors, formats).
• 🚀 Speed: Fewer one-off measures → faster build, easier maintenance.

Here is a short demo on how they work:

They can be defined in Power BI Desktop using the DAX query view (DQV) or TMDL view. I personally prefer the DQV view and will show next how you can simply create one that lives in your model afterwards. For a deeper dive…