When will most teens hit the pubertal growth spurt?

Varies. There are "early bloomers" and "late bloomers". Early puberty occurs in middle school and late bloomers hit growth spurt in 9-10th grades. Girls do the bulk of growing the two years before menses and boys will hit growth spurt (on the average) between 12-14 years and can grow until age 20 . I always ask parents when they hit their growth spurt as that provides idea when their children might..
Growth spurt. For males growth spurt is toward the end of puberty ie 15 to 16 years old. For girls it's in the middle ie 11 to 12 on average. It really depends on pubertal staging.