At what age do teens stop growing?

varies: It all depends on the age of the onset of puberty. Most people stop growing a couple years past puberty but some people continue to grow even into their college years. It varies with the individual.

Puberty decides: Every teenager is different but they all go through the same basic stages of puberty. These stages are often referred to as tanner stages (also referred to as sexual maturity level). Stage i is seen before puberty starts and stage v is when you have full adult characteristics. Once you are at stage v you are unlikely to grow any taller. Typically this is at ~15-16 for girls and ~16-17 for boys.