How tall am I going to be by the time Im 18?

I'm 15, turning 16 in 2 1/2 month's. My dad and mom are not tall, my dad is 5'9 and my mom is 4'10. I'm 5'8 1/2, but I have 2 half brothers who are 6'0 and 6'1. My dad believes they inherited from my grandfather who was 6'0. I have an uncle is 6'3. I also heard if you have big feet you also have a chance of being tall. I wear a size 13 american. I know it's silly because I dont want to be called the runt because I am the youngest.