Honestly, it would probably be best to discuss this with your Account Manager (AM). The only reason that I say this is because depending on what concurrent license you are wanting to figure out depends on the usage of it as well as the department using it. For example, workflow concurrent licensing can be thought of this way. If you are going to have a whole department using it all the time, then you would want a license for every single computer in that department that users will be logged in to using the system. However, if you are also going to be having random users outside of that initial department using workflow, you might only budget getting 1 concurrent license for every 5 users or so.
So as you can see, it really depends on what concurrent license you are going to be using as well as what department will be using that license and lastly how will that license be used across the enterprise. So your AM would definitely be able to help with this and give you a good rough equation on how to determine how many to buy of the concurrent license you are looking at.
