What level of U.S. high school Spanish do you think this entire duolingo Spanish course is equivalent to? Spanish 1, 2, or 3?
I doubt you can even consider a comparison because there is next to no speaking component within Duolingo. Yes, you use a mic and say sentences but it is barely evaluating your pronunciation. I've made obvious mistakes as I spoke and it has been accepted as correct. You aren't composing your own sentences as you would be required to do in a class. So that whole aspect of communication is not being taught.
I suggest you call a U.S. high school and ask them what level of Spanish their students have at the time of their final exams. Then you can have yourself tested online or at some kind of institute and see how far you get. :) I suggest you take a very detailed test, one that takes at least an hour.