Thank you for your suggestion, but I was looking for a way to identify how long each section (or the header in my TOC) is (as a matter of fact, I'm interested in how many pages each Chapter is basically). Otherwise, your suggestion could act like a TOC not depending on 'paragraph level's (and thanks for introducing bookmarks to me

I could just use a calculator and check with the TOC and do some calculations, but you don't know what your automation passion will lead you