The DAX language

DAX — short for Data Analysis Expressions — is the formula language used in some of Microsoft’s most powerful data tools. If you’ve worked with Power BI, Excel’s Power Pivot, or SQL Server Analysis Services (Tabular), then you’ve already seen DAX in action.

At its core, DAX lets you create custom calculations. Not just simple math, but things like ‘year-to-date sales’, ‘running averages’, or ‘dynamic comparisons between different periods’. It works with entire tables and columns, not just individual cells, and it’s especially good at handling large volumes of data, working with dates and time, and using the relationships between different tables in your data model.

But here’s the thing: DAX is different. It looks a bit like the formulas in Excel, but it behaves in its own way. It has its own rules, its own logic, and its own way of thinking about filters, context, and data flow. And that’s exactly why DAXplained exists.

I created this site to help you understand DAX, step by step, without the jargon. We break down the key ideas, show you real-world examples, and explain how and why things work the way they do. Whether you’re just starting out or trying to solve a tricky calculation, you’re in the right place.

Let’s make DAX less mysterious, and a lot more useful.

Updated Articles

On the ‘Updated Articles’ page you can find a range of articles updated with original examples, distinct from the Microsoft documentation. Click below for an overview of these articles.

About this Reference

This reference contains elaborate information on the DAX language. The Guide is updated regularly to reflect the latest changes in Microsoft products. Each DAX function is presented with a syntax, supporting articles and often with examples.

While this Power Query Guide is a BI Gorilla project created and maintained by Rick de Groot, it also incorporates official Microsoft documentation to provide you with the most accurate and up-to-date information.