Pitch Speed Equivalent Calculator
How fast does your Little Leaguer's fastball "play" compared to a high school or big-league pitch? Put in the speed and the mound distance, and this works out the speed that would give a hitter the same time to react from 60 feet 6 inches.
I coach youth teams, and parents often ask me what a speed means on the big field. This is the math I use to answer that. It's an estimate, and I'll show you exactly how it's worked out below.
Equivalent speed at 60.5 ft
78.9 mph
127.0 km/h · estimate
| Your pitcher | Compare | |
|---|---|---|
| Mound distance | 46 ft | 60.5 ft |
| Release extension | 4.18 ft | 5.5 ft |
| Release to plate | 41.82 ft | 55 ft |
| Speed | 60.0 mph 96.6 km/h | 78.9 mph 127.0 km/h |
| Reaction time | 0.475 s | 0.475 s |
Same time to the plate at both distances. Ignores drag and movement, so treat it as an estimate.
Want to know your real speed? Measure it with a radar gun.
Our radar gun guide →Budget picks under $100 →How to measure pitch speed →
How the math works
In plain words: the equivalent speed is the speed that covers the longer distance in the same time.
- Work out how far the ball really travels: the mound distance minus the release extension (how far in front of the rubber the pitcher lets go).
- Reaction time = that distance ÷ the pitch speed (in feet per second; 1 mph = 1.4667 ft/s).
- Equivalent speed = the compare distance (minus its extension) ÷ the same reaction time.
Which boils down to: equivalent speed = speed × (compare release-to-plate distance ÷ your release-to-plate distance). km/h = mph × 1.609344.
The default extension is 5.5 ft at 60.5 ft, scaled down in proportion for shorter mounds (about 4.2 ft at 46 ft). That's a ballpark, not a measured figure for your kid. You can change it under Advanced.
Hand check: 60 mph from 46 ft. The ball travels 46 − 4.18 = 41.82 ft. At 60 mph (88 ft/s) that takes 41.82 ÷ 88 = 0.475 s. To cover 60.5 − 5.5 = 55 ft in 0.475 s you need 115.7 ft/s, which is 78.9 mph (127.0 km/h).
Quick reference: 46 ft to 60.5 ft
Little League speeds and their 60.5 ft equivalents, using the default extension settings. These come from the same formula as the calculator.
| Speed at 46 ft | Reaction time | Equivalent at 60.5 ft | Equivalent (km/h) |
|---|---|---|---|
| 40 mph | 0.713 s | 52.6 mph | 84.7 km/h |
| 45 mph | 0.634 s | 59.2 mph | 95.2 km/h |
| 50 mph | 0.570 s | 65.8 mph | 105.8 km/h |
| 55 mph | 0.518 s | 72.3 mph | 116.4 km/h |
| 60 mph | 0.475 s | 78.9 mph | 127.0 km/h |
| 65 mph | 0.439 s | 85.5 mph | 137.6 km/h |
| 70 mph | 0.407 s | 92.1 mph | 148.2 km/h |
50 ft to 60.5 ft
| Speed at 50 ft | Reaction time | Equivalent at 60.5 ft | Equivalent (km/h) |
|---|---|---|---|
| 45 mph | 0.689 s | 54.5 mph | 87.6 km/h |
| 50 mph | 0.620 s | 60.5 mph | 97.4 km/h |
| 55 mph | 0.563 s | 66.6 mph | 107.1 km/h |
| 60 mph | 0.517 s | 72.6 mph | 116.8 km/h |
| 65 mph | 0.477 s | 78.7 mph | 126.6 km/h |
| 70 mph | 0.443 s | 84.7 mph | 136.3 km/h |
| 75 mph | 0.413 s | 90.7 mph | 146.0 km/h |
What this doesn't tell you. It doesn't predict how hard a kid will throw when they move up, and it isn't a rating of how good they are. A pitch also slows down on the way to the plate, and this math ignores that. Use it to put a number in context, and don't push a young arm to chase it. See age-appropriate velocity and pitch limits for young pitchers.
Embed this calculator
Run a league or team site? You're welcome to put this calculator on it. Copy the code below and paste it into your page's HTML. It's free and loads from this site. On a narrow column, raise the height to about 1150 so nothing gets cut off.
More tools
All the calculators live on the tools page. To get an actual speed reading, start with how to measure pitch speed or our radar gun guide.
FAQ
How do you convert Little League pitch speed to MLB speed?
Take the distance the ball actually travels at each level (mound distance minus the release extension) and scale the speed by the ratio, so the batter gets the same time to react. With the default settings, 60 mph from 46 ft works out to about 78.9 mph from 60.5 ft. It's an estimate, not a prediction of how hard the kid will throw later.
Does a 70 mph Little League fastball equal a 92 mph big-league fastball?
In reaction time, roughly yes: with the default extension settings, 70 mph from 46 ft gives the hitter about the same time as 92.1 mph from 60.5 ft. It doesn't mean the pitcher throws 92. The ball's actual speed is still 70 mph.
What is release extension and why does it matter?
Pitchers don't let go of the ball on the rubber. They stride forward and release it several feet in front of it, so the ball travels less than the full mound distance. The calculator subtracts that. The default is 5.5 ft at 60.5 ft, scaled down for shorter mounds because smaller kids take shorter strides. You can change it under Advanced.
Why do I get the same answer as a simple distance ratio?
Because when the extension is scaled in proportion to the mound distance, the scaling cancels out and the result equals speed × (compare distance ÷ mound distance). Turn off "Scale extension" or change the number under Advanced and the result will shift. If your pitcher has a long stride for their age, a fixed extension gives a higher equivalent.
How accurate is this?
It's an estimate. It assumes the ball travels at the same speed the whole way, and it ignores air drag, movement, pitch type and where the hitter makes contact. It's good for comparing levels, not for scouting reports.
Can I put this calculator on my team's website?
Yes. Copy the embed code in the Embed this calculator section and paste it into your page. It's free.