Power BI Master Class-Data Models and DAX Formulas (Udemy.com)
Master DAX in Power BI - build data models, write measures and time intelligence that give you numbers you can trust
Created by: Ian Littlejohn
Last updated September 2026
What you will learn
- Write DAX measures with CALCULATE, ALL and ALLEXCEPT so your numbers respect the filters you intend and ignore the ones you do not
- Build time intelligence measures for year-to-date, prior period and year-on-year comparisons
- Use the iterator functions - SUMX, MAXX and RANKX - for calculations that work row by row
- Create relationships between tables, and use USERELATIONSHIP when one relationship is not enough
- Build virtual tables and cross-table calculations for questions a single table cannot answer
- Segment customers and build scenario models using SWITCH and What If Parameters
- Design a date master table and a star schema so the model stays fast as the data grows
- Work through case studies on DirectQuery, Quick Measures, Performance Analyzer and the DAX Query View
How it compares
Against the other 68 rated Udemy courses in Power BI on CourseDuck:
- Rating4.6 out of 5higher than 55% of them
- Reviews8,151#17 of 69 by number of reviews
- Length4.2 hoursshorter than 77% of them
- Last updatedSeptember 2026more recently than 80% of them
Course Description
This course contains the use of artificial intelligence.
Every lesson in this course is written, created and recorded by me. AI is used only to help produce supporting images and written materials around the lessons.
Your report looks right and the numbers are wrong. The total does not match the sum of the rows, the percentage changes when somebody clicks a slicer, and last year's comparison quietly stops working in January.
That is a data model and DAX problem, and this course is about fixing it properly rather than working around it. You will build the model, write the measures, and understand well enough why a number comes out the way it does that you can debug the next one yourself.
COURSE CONTENT AND OUTCOME
Write DAX measures with CALCULATE, ALL and ALLEXCEPT so your numbers respect the filters you intend and ignore the ones you do not
Build time intelligence measures for year-to-date, prior period and year-on-year comparisons
Use the iterator functions - SUMX, MAXX and RANKX - for calculations that work row by row
Create relationships between tables, and use USERELATIONSHIP when one relationship is not enough
Build virtual tables and cross-table calculations for questions a single table cannot answer
Segment customers and build scenario models using SWITCH and What If Parameters
Design a date master table and a star schema so the model stays fast as the data grows
Work through case studies on DirectQuery, Quick Measures, Performance Analyzer and the DAX Query View
A NOTE ON COPILOT AND AI
You may be wondering where Copilot fits in. Copilot in Power BI runs on a Microsoft Fabric capacity, which is something your organisation buys and switches on - not something you can enable yourself. Most people learning Power BI do not have it, and will not have it for a while.
There is a second reason it matters less here than you might think. DAX is where reports go wrong quietly, and a wrong measure does not look wrong - it looks like a number. Whether you write it yourself or something writes it for you, you still have to be able to read it and say whether it is right. That is what this course teaches.
ABOUT THE TRAINER
I have been training business people to work with data since 2008, and publishing on Udemy since 2013. I now have 16 live courses with more than 400,000 students and more than 139,000 reviews, at an average rating of 4.6.
I teach Microsoft Power BI, Microsoft Excel, Copilot in Excel, Looker Studio and Amazon QuickSight. What makes my courses different is that I teach the analysis, not just the tool - every lesson starts with a business question someone actually asks, and shows you how to answer it with software you already have.
WHAT STUDENTS ARE SAYING
This course is great, it revealed to me functions that I never thought existed. I cannot wait to apply these in real time scenarios. Thanks Ian you are doing a great job.
Coming from Spotfire (after company decided PowerbI is cheaper) with its slightly different approach, this course helped to gain some traction with PowerBI
I felt quite comfortable using Power BI, but this course opened my eyes to many more possibilities the tool offers. I really appreciate the straightforward, no-nonsense and easy to follow teaching style from the instructor. Highly recommended to all who have been using Power BI and are ready for the next step.
The training data files, the practical activities and the case studies are all included. Enrol now and by the end you will be writing measures you can explain to somebody who asks where the number came from.
Instructor Details
- 4.6 Rating
8,151 Reviews
Ian Littlejohn
I specialise in training business users to learn powerful methods and techniques to transform data into useful information and intelligence as well as learning strong data analysis methodology.
I completed my university degree in economics and emerged keen and eager to change the world. I spent the first half of my career working for multinational companies, on projects of various sizes, in different sectors, all revolving around analysing data of some sort and working with different software products, including Microsoft Excel.
I found that so many Excel users had a very basic understanding of how Excel works, and instead of using Excel to do the work for them, were doing all the work themselves, using old spreadsheet technology like macros instead of embracing technology like Pivot Tables. Pivot Tables were actually introduced into Excel in 1994 but many Excel users have avoided using them because they seem complicated and difficult to use.
In 2008 I decided to start my own training company and this was borne out of the passion I had to teach Excel users how to work smarter, not harder. As technology evolved, and new systems developed, I continuously expanded my training to include Power BI, Amazon QuickSight, Looker Studio, and most recently Copilot in Excel and Microsoft 365 Copilot.
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Reviews
By Mirela Szweda-Siąkała on 6/23/2026
I don't feel that my level of knowledge has improved. There were too few practical examples, which made it difficult to fully understand and apply the concepts.
By Marieke Verhamme on 1/29/2026
De cursus ging vlot, komt ook met oefeningen. Sommige measures werden meer behandeld dan andere, zelf ben ik nog op zoek naar meer context (wanneer X-functies gebruiken, wanneer nieuwe kolommen toevoegen, wanneer gewone measures creëren). Qua inhoud ; heel duidelijk en natuurlijk gebracht met duidelijk beeldmateriaal.
By Saarthak Agarwal on 3/29/2025
Superb! I genuinely enjoyed this insightful course on Power BI. It was an eye-opener and truly enriching. Now, the real journey begins—it’s all about my practice and dedication from here on. I am well aware that the road ahead won’t be a walk in the park, but as they say, ‘Rome wasn’t built in a day.’ With consistent effort and perseverance, I am confident that I will master the art of data visualization and analysis. A big shoutout to the trainers and organizers for making complex concepts seem simple and easy to grasp. The hands-on approach and real-world examples made the learning experience incredibly practical and engaging. Now, it’s time to roll up my sleeves and dive deeper. After all, ‘practice makes perfect,’ and with determination, I am ready to turn this knowledge into skill. Thank you once again for this amazing learning experience—it was truly worth every minute!
By Ed Kuiters on 2/25/2024
I felt quite comfortable using Power BI, but this course opened my eyes to many more possibilities the tool offers. I really appreciate the straightforward, no-nonsense and easy to follow teaching style from the instructor. Highly recommended to all who have been using Power BI and are ready for the next step.
By Shaun Morris on 6/21/2023
Although tthe course really only touches upon the huge subject that is DAX it does it in a way that prises open the door to further study by giving yoiu enough to get you started without overloading you. I really rate the course but I do feel that it needs to be one of a series of courses rather than being considered a one stop mastering of DAX learning experience. Many thanks for another great course Ian.
By Shivanand Raskonda on 5/7/2022
Thank you for creating this course. I am searching this type of content on youtube finally i am move udemy. Before :- I am unable to write dax queries. Now:- Easily write dax queries. I am working as Power BI Developer due to dax my performance go down at my workplace. Now happy announce this course give the confident and improve performance as well. Thanks. Beginners recommend to learn dax.
By Deepak Holla on 3/1/2021
Hi Udemy Folks, This is an excellent course for understanding the complicated topics of Data Models and DAX Formulae in Power BI. Ian has explained all key concepts in an easy to understand manner. All topics are are up-to-date as on 03-Mar-21. It is my 2nd master class course of Ian. I would like take this oppurtunity to thank Ian for putting this course together. I am about to start the last Master Class, Power BI Master Class - Dashboards and Power BI Service 2020!!! Regards, Deepak.
By Dare ODEYEMI on 11/14/2020
Its been good so far
By Ilker Uyanik on 11/14/2020
you need to add practice page for time intelligence functions
By Kamil Karbowski on 11/7/2020
Good Course, really great overview on possibilities and features.
By Vaka Sudhakar Reddy on 10/23/2020
great exposure to start working on practical data models and visualizations. Thanks a lot. Regards.
By Dafydd Prys Ap Morus on 10/21/2020
Very good course with a no nonsense approach for intermediate Power BI users, excellent pace and detail.
Quality Score
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Overall Score : 92 / 100










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