The machines tell you exactly how much time is left.
I did four loads, and the dryers got almost everything dry on the first run through. I had to do about 10 minutes extra for a couple pair of jeans, but everything else was dry the first time through. Some things I even took out early.
I think one of the reasons some people have to run the dryers for two and three cycles is that they are overstuffing them. They are not as big as your average washer/dryer at home, and only hold half to 3/4 of the laundry load.
Anne