Getting a percent of total measure working in DAX, understanding how it’s working in a non vague way can be quite a bit trickier. Really it is an ideal pattern to learn some of the underlying behavior of DAX.
In this video, we take a very simple percent of total measure and let you poke behind the curtain to see what’s happening internally at each step of evaluation. If you’re new to DAX or you’ve been doing it for a while but feel your understanding is very cursory this video may help snap a lot of things into focus for you.