Find out default inspector height

Hi,
i wonder if there is a way to calculate default inspector height?
I am doing my own editor window where i am drawing my own smaller windows with GL. My problemy is that i want them to resize when content (default inspector of Scriptable Object) is expanded (like toggle list). Any ideas how can i achive that?
Right now i am using scrollView but i really need them to resize. I wanted to get scrollView max height from its vector2 since i belive it is pixel size of hidden arena but i cannot find any acces to it.

you set the size of the inspector at the end, the best way is to every time you put a label or something like that you sum the line space it ocuped.