How Hard Does the Average 13-Year-Old Throw?
About 65 mph, and that is a real jump from age 12. The leap is mostly growth, and it brings a temptation worth resisting.
The quick take
- The average 13-year-old pitcher throws roughly 65 mph, a notable jump from 12U.
- Most of that jump is puberty and growth, not training.
- The danger at 13 is chasing the velocity surge with more throwing, showcases, and breaking balls.
- This is a prime age to protect the arm, because workload is climbing right as the body changes.
The short answer
~65 mph
The average fastball for a 13-year-old (13U) pitcher, a meaningful step up from the roughly 55 mph average at 12.[1]
Thirteen is often where the radar gun jumps, and it can feel like the training is finally paying off. Some of it is. But most of the leap from 12 to 13 is simply growth, as kids hit puberty, add size, and get stronger almost for free. That is worth knowing, because it shapes how you should respond to it.
Why 13 is a turning point
The velocity surge at 13 tends to bring three temptations at once: throw more, start hitting showcases, and add a breaking ball. Each one feels like the natural next step. Together they are exactly the recipe that the research links to arm injury in young pitchers, because workload climbs right as the body is changing fastest.
The curveball question at 13
Thirteen is the age the breaking-ball debate gets real. The honest answer is that overuse matters more than pitch type, but a young pitcher who has not mastered the fastball and changeup, and who lacks the control and maturity to throw a breaking ball well, is the one to worry about. We break down the evidence in curveballs, velocity, and weighted balls.
What matters more than the number
At 13, ride the natural velocity gains and protect the arm that is producing them. Stay inside age-based pitch counts, watch for arm fatigue, and build velocity through the body rather than through max-effort shortcuts. The kids who stay healthy through this stretch are the ones still throwing hard at 17.
Common questions
How hard does the average 13-year-old throw?+
About 65 mph, a notable jump from the roughly 55 mph average at age 12. Most of that increase comes from growth and puberty rather than training.
What is a good pitching speed for a 13-year-old?+
Anything around 60 to 70 mph is typical. Throwing below that is common, especially for kids who have not hit their growth spurt yet, and it usually catches up.
Should a 13-year-old start throwing curveballs?+
Only once he has mastered the fastball and changeup and has the control and maturity to throw a breaking ball with sound mechanics. Overall throwing volume matters more for injury risk than the pitch type itself.
Sources
This article is reviewed against the research below. Where findings are debated, we say so in the text rather than overstating the certainty.
- 1.Professional Baseball Strength & Conditioning (PBSCCS). How Hard Should You Throw? (youth velocity averages by age). PBSCCS. https://pbsccs.org/how-hard-should-you-throw/
This article is education, not a medical diagnosis, injury prediction, or treatment plan. If your pitcher has pain or you have concerns about an injury, consult a qualified sports medicine professional.