How did you calculate your goal weight?

At my first follow up my surgeon set a goal of 160 based on my loss at one month. I was not content with that but accepted it at the time . At my 3month visit I revisited the subject and we agreed 135 would be achievable for my height and age. It is also based on body type and health issues. No number is set in stone though. Your body will let you know as well. Also keep in mind if you haven't had skin removal you will be a few pounds heavier as well but probably not as much as you would think. So just do your program and don't focus too much on one particular number. The weight will come off and for most will level out where you should be. 

I'm also 5'8" and my highest weight was 320, so we are close. My surgeon calculated my goal weight to be 180. I don't know if that was based on the percentage of weight he wanted me to lose, or what. My personal goal weight is 164, because that would put my BMI just into the "normal" range. :)

I threw a dart. Almost literally. I just picked a weight that I thought sounded relatively healthy and that seemed reachable, so I ended up with 150. I don't think I've weighed that since maybe fourth or fifth grade, to be honest. My surgeon has a different idea that he only just shared with me at my last visit a week ago: 131! Although he did back off a little and say he'd be happy if I got to 140. So, with 150 being about 24.2 BMI, which is at the high end of normal, and 131 being a BMI of 21.1 which is toward the lower end of normal, I'll end up being happy anywhere in the middle of that. 

I pulled it out of the thin air because my surgeon steadfastly refuses to give goal weights. I don't only take weight into account; I also use body fat as a factor, which is a good indicator of health. I am four pounds below my goal weight. My body fat right now is 28%. I am working on getting it to 25%. I think it is important to look at your health as a whole, not just your weight.

I used my mother's weight (she was the same height as I), and added 10 lb (she passed at 42 and I am 58 now).  I have a small frame and although I am now a normal BMI (HOORAY!!), I still have a lot of weight in my hips and belly so should have no trouble losing to goal.  Right now I am severely 'stuck' on a long plateau and I am sure it's because this weight is where I always managed to get down when I lost in the past.  I used to give up around this point but no longer - I know if I keep active and stay on the plan it'll move again.  I should hit goal this summer :)

I picked a number the was in the middle of my "healthy weight" BMI, which is 125 :)