How do you figure out your goal weight?

I CAME OUT OF HIGH SCHOOL 6'1' MUSCULAR AND AT 240LBS. (sorry for the CAPS) I went into the army and got down to 185 lbs but I was into boxing, martial arts, racquetball, football, basketball and many sports-also I was told that I had a loss of muscle mass, they wanted my walk around weight to be 205lbs so I would lose weight for competitions. Once out of the Army my best weight was around 225-235 lbs before I blew up over the years to 347lbs! So I want to get lower than 225 lbs to around 200 lbs to lose the fat and then build muscle up to around 225-235lbs. As long as I am healthy I've always enjoyed being a little bit larger than my friends so If I get to that weight with muscle I would be happy and hopefully able to maintain. I definitely have a lot of weight to still lose around my belly, butt and back so I'm into resistant training with weights hoping that will help. In the interim I'm enjoying getting healthy and having goals to work toward. I've stopped concentrating on just the weight itself but also on health, nutrition and body shaping, pounds cannot be our only barometer although it is probably what gives us the most encouragement!

I had surgery almost 9 years ago so my memory may not be 100% correct but I believe my surgeon set a goal of 80% of the excess weight I needed to lose with my goal weight being in the middle range of the BMI chart. Back then 80% was the average people lost and maintained... I believe most people lost more then would experience a 10% regain?

My goal... I made mini-goals because I felt they were easier and less overwhelming than one far off goal. Ideally I wanted to be healthy, not overweight and to be able to shop in non-plus size sections/stores... but my original goal was to be under 250lbs, then it was to get to under 200lbs... then I wanted to hit my surgeons target (no idea what that was 165 maybe?)... then it was to get under 150 and stay there (so I was closer to 100lbs than 200lbs, lol).