For my personal dosing of ivermectin for 160 lbs. I use one #00 capsule and the dosage fills the long end about 3/4 of the way. The only thing is, I don't know if the brand I am using is the same as every other brand that others may use. What I did was decide which brand I was going to stick with and determined that the first time, until I figured out the correct dosage, I would have to waste the first amount so I could get the plunger to zero so I could calculate correctly. I then made a mark on the plunger and the container at the same spot so that I could tell when I had made a complete rotation. I figured that the correct amount for my 160 weight was one complete rotation and six additional notches. The youtube video that sharkman advises really helped me. It's important to figure it out for your own body weight and the brand that you are using, because if you decide to take additional meds you can transfer your knowledge to those other meds. I just fill the capsule now and don't worry about any waste at the beginning of each tube because I can tell just by looking at my capsule. I hope this helps. But remember, I don't know your brand so 1 full rotation plus 6 notches may not apply to anyone else.