There is no definite age as to when you stop growing but the human body grows steadily from birth and by the late teens, the skeletal system has fully formed. You are likely to grow taller after the age of 20 but scientists discovered that some bones never stop growing as you age.
It depends. You will stop growing if you need to. Because I am a little slow in growing and I'm 14 and still 4'4"! Lots of people call me short but the doctor says that I could still be growing until I'm 20+! But only if I need it!