Do Baseball Radar Guns Work on Cars?

Often, yes. A radar gun uses the Doppler effect to measure how fast something is moving toward or away from it. A car is a much bigger radar target than a baseball, so a gun that can read a fastball can often read a car, as long as the car's speed and distance fall inside the gun's limits.

A few guns are built for both. Bushnell's manual for the Velocity, for example, lists a race-car range of 10–200 mph at up to 1,500 ft, compared with 10–110 mph from up to 90 ft on a baseball. See our Bushnell Velocity page. Other guns, like the Pocket Radar Ball Coach, are designed and specified for balls only.

What the gun actually measures

A radar sends out a radio signal. When it reflects off a moving object, the signal's frequency shifts. The faster the object moves toward or away from the gun, the bigger the shift. The gun turns that shift into a speed.

(The original version of this post said a radar gun times how long the signal takes to bounce back. That's how distance-measuring radar works, not a speed gun. We've corrected it.)

Getting a good reading

• Stand still. If you're moving, your motion gets mixed into the reading. Most sports guns are meant to be used from a fixed spot.
• Get in line with the car. Like a pitch, a car driving across your view at an angle reads low. The closer you are to straight down the road, the better.
• Stay safe. Never stand in the road. Stand well off the shoulder, ahead of a straight section.
• Pick one target. With several cars, the gun may read whichever is strongest or fastest.

A car driving in a circle around you would read near zero, because it isn't getting closer or farther away.

It's not speed enforcement

Sports radar guns aren't certified enforcement devices. Use them for fun, for racing or for checking a car in your driveway, not as evidence of anything.

Want a gun that does cars and baseballs? See our Bushnell Velocity page →