36 exp requires 54" plus leader and taped end. An 8" leader and end combined will make the total length 62". 100 ft = 1200". You should get 19 rolls if you are careful not to waste too much everytime you open the film loader. If I were bulk loading today I would make 12 exp rolls for the same reason as stated by others. I rarely use all 36 exp at one time. I cut the film in the camera in the darkroom and make a new tongue for the remaining unexposed film after I get the exposed film in the reel. It is a bother, but the films I buy from J&C are available as 36 exp only.
I have given up on bulk loading because reusing cartridges increases the chance of scratching film. IMO the time and effort required to make the exposures is worth a lot more than the small amount saved by bulk loading. The only reason I would bulk load today is if I found an unusual film available in bulk only.