You should get 18 rolls at 36 exp each. I do, at least. Depends, too on how long you make your leaders, and how much film at the end of each roll is light struck. Some bulk loaders have a shorter distance from the feed out opening to the cassette take-up crank opening, so the end of the film, where it is taped to the spool could have from 1 1/2 to 3 frames exposed to light, depending upon your loader.