Following copied from Steven Ellis (can be found in articles on this website) & a really good range for pitching speeds by age.
Average Pitching Speeds Of 10 Year Olds, 11 Year Olds, 12 Year Olds, 13 Year Olds, 14 Year Olds And 15 Year Olds
By Steven Ellis, former Chicago Cubs pitching pro
An important aspect of pitching which must not be overlooked is velocity. Many pitchers strive to achieve a high velocity, and the fact is that college and MLB scouts look heavily at a pitcher’s fastball velocity. Coaches as young as the Little League age seem to put a lot of emphasis on fastball velocity and how hard a pitcher can throw. For those of you looking to see where your velocity falls in your age group, read on!
10 Years Old and Younger
The average fastball velocity for pitchers 10 years old and younger is between 40-50 mph. The average change up speed for this age group is about 10 mph slower, putting the velocity between 30-40 mph.
11 and 12 Year Olds
Pitchers in this age group are playing in the Majors division in Little League. The average fastball is between 50-60 mph. However, at this age the players may start to hit puberty, therefore it is not uncommon to see a pitcher throwing near 70 mph. The changeup velocity at this age is typically between 40-50 mph.
13 and 14 Year Olds
The pitchers in the 13 and 14 year old age group can be heavily involved in travel baseball, or finishing up their Little League experience. A typical fastball from this age group is anywhere from 55 mph (on the low side) to 75 mph. A pitcher throwing 75 mph is well above average for this age, and their fastball is at a high school caliber. An average changeup for this age is somewhere around the 50-60 mph mark.
A high school pitcher can be anywhere from 14 to 18 years of age. This plays a factor in determining an average fastball velocity, however keep in mind that most high schools have a Freshmen, Sophomore, and Varsity program to break up the large age gap. On the average, a typical Varsity high school fastball is between 75-85 mph, although many good Varsity pitchers will be seeing the upper 80s and low 90 range. The Freshmen pitchers will usually be throwing at a comparable speed to the 13 and 14 year olds, and the Sophomores will lie somewhere in the middle. A good changeup for a high school pitcher is a -10 to -15 mph drop, so anywhere from 60-75 mph is common.
College and Beyond
Once a pitcher leaves high school, they have most likely reached their maximum fastball velocity, although some small gains are definitely possible. The average fastball for these upper level pitchers are 90 mph, but there will always be some guys who can light up the radar gun near 100 mph. At the lower levels of college baseball, there will still be guys in the low to mid 80s. Changeups for this group should be at about a 15 mph drop, bringing the velocity near the upper 70s.
If your fastball velocity is not up to par with your age group, don’t be discouraged! It is very likely that you are still growing, and your velocity may continue to increase. These numbers are an estimate, and there are no set rules about how hard you must throw. Look at Greg Maddux! He throws the ball in the mid 80s and is considered one of the best in the game.
Keep working hard at your game, and use these numbers as only a reference.