What age do guys normally have their growth spurts??
you never really know. I know of a case where a young boy had his growth spurt at the age of only 9! and I also know someone who was 5'1 all through highschool and by the time he finished college he was 6'5! It depends on the person.
all 3 of my brothers didnt start growing a lot till they hit 16 years old.
the big one I think is 16