How tall will I be when I'm fully grown? I'm 15 years old and I'm currently about 5' 8.5". But I don't think I've had a growth spurt yet, I've grown in a steady pace. I have really long legs and arms. Although, My arm span is about 6' 1.5". Could this mean I could be that tall or at least 6' tall? I also have really long skinny fingers (if that information is any use). My dad is about 5' 7" and my mom is 5' 1". I've been told I look like my great grandfather and he was a tall man (about 6 feet tall), so do i have his genes? I know this is a lot of information... So could you predict how tall I might end up?