Download DAX Studio
DAX Studio is a superb tool to develop and troubleshoot DAX calculations, as it gives you a way to visualize tables as they are internally represented during the computation. DAX Studio helps you to understand how your filtering actions are being applied across the tables which become active during the evaluation of the expression.With more advanced DAX calculations, you will need to use intermediate ‘filtered tables’ to arrive to a specific output.
DAX Studio is a great tool for unit testing, developing DAX query, and querying performance statistics, as it's able to write, execute, and analyze DAX queries in Power BI Designer, Power Pivot for Excel, and Analysis Services Tabular.
It comes with an array of useful tools including an Object Browser, query editing and execution, formula and measure editing, syntax highlighting and formatting, integrated tracing and query execution breakdowns.
If you need to run DAX queries against Excel PowerPivot models or Analysis Services Tabular models, then DAX Studio is a great tool for the job.