Are Baseball Radar Guns Accurate?

Yes, a good radar gun used the right way is accurate. Most quality guns today publish an accuracy spec of about ±1 mph. For example, Pocket Radar rates its radars at ±1 mph, and Bushnell's manual for the Velocity lists ±1 mph too. That's the maker's spec; we haven't lab-tested any gun ourselves.

The catch is the second half of that sentence: used the right way. Most bad readings come from the person holding the gun, not the gun.

What throws readings off

Angle (cosine error)

A radar measures the part of the ball's speed coming straight toward or away from it. Stand off to the side and the gun reads low. At 10° off-line, a 90 mph pitch reads about 88.6 mph; at 20°, about 84.6 mph. Stand directly behind the catcher or the pitcher, in line with the pitch. Our how a radar gun works article has the full table.

When the ball is measured

A pitch slows down on its way to the plate because of air drag. A gun that reads near release will show a higher number than one that reads near the plate. That's why your gun might not match a TV broadcast, which reports release speed from Statcast.

Wrong target

A radar can lock onto the strongest or fastest thing it sees: the pitcher's arm, the bat, a swinging catcher's mitt, or a car behind the field. Aim carefully and keep the beam on the ball's path.

Interference and conditions

Other radar units, strong electrical sources and heavy rain can interfere. Cold can affect some guns too; Bushnell's manual lists an operating range starting at 32°F.

Low batteries

Weak batteries can cause missed or erratic readings on many guns. Charge or replace them before a session.

How to check your gun

• Tuning fork: some makers sell a calibrated tuning fork. Pocket Radar sells one rated at 65 mph that you can use to check any of its radars.
• Side-by-side: compare with another gun at the same spot, both in line with the pitch.
• Consistency: throw a series of pitches. Readings should cluster, not jump around.

For a routine that keeps your gun reading right, see how to use and maintain a baseball radar gun.

Looking for an accurate gun? See our guide to the best baseball radar guns →