How do you know when your puberty  has stop?

Interesting Question. People are usually worried worried about late or early onset of puberty. You are worried about when it will stop. Perhaps you are concerned about too much or too little of something about what puberty has done to your body. Please meet with your physician to address your specific concern. Puberty stops at 17 (girls) and 18 (boys) usually. See wikipedia for detailed review on puberty.