When pull up bars recommend door frame sizes, are they measuring from the inside or the outside of the frame?

When doorway pull up bars say "fits doorways 24-33 inches", do the measure from the inside (the space) or the outside of the frame. I ask this because measuring from the inside my doorway is 24-25 inches. Buy from the outside of the frame it is 33 inches.

I have space on either side of the frame, from where the door opens into (you pull to open). But I have no space on one side of the door frame, from where the door opens and moves away from you (you push to open).