What is the average height of a 13-year-old?
Boy: The average is about 62" with 9/10 boys being 56"-67" tall.
Girl: The average is about 62" with 9/10 girls being 57" - 68" tall.
The height of a child in puberty is very diverse due to the fact they are having growing spurts, so they could be much shorter or much taller than the average. It is nothing to worry about and they continue growing until around 20-years-old.