How to Measure the Speed of a Thrown Ball

Estimating the speed of a thrown ball is important in many sports, from baseball to cricket. There are many different products promising to measure the speed of a ball. Major League Baseball teams use radar guns. These are the same radar guns that are used to measure the speed of a car. A trainer stands behind the catcher, pointing the radar gun at the pitcher. But there are ways to estimate ball speed without expensive equipment.

Things You'll Need

  • Tape measure
  • Small flags or markers
  • Thrower
  • Catcher
  • Ball
  • Stopwatch with hundredths of a second
  • Video camera (optional)
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Instructions

    • 1

      Choose a spot for the thrower and place a flag. Measure 40 feet from the thrower's spot. Mark the distance with a flag. Depending on the strength of the thrower, longer distances may be used.

    • 2

      Ask the thrower and catcher to stand on the marks.

    • 3

      Start the stopwatch as the ball leaves the thrower's hand. Stop the stopwatch when the catcher touches the ball.

    • 4

      Divide 40 (the distance in feet) by the number seconds it took to throw the ball from one person to the other. This is the feet per second speed.

    • 5

      Multiply the feet per second by 0.681818181818182 to determine the speed in miles per hour.