Things You'll Need
Instructions
Set up a target at a medium distance. Too far and your arrow may slow down, while too close and you may get inaccurate readings. Try 30 or 40 feet.
Have a friend hold a stop watch and keep time. Once you shoot the arrow they should start timing, hitting stop when your arrow hits the target.
Take the number reading from the stop watch and put it over the distance you shot the arrow. So 40 feet in 7 seconds would be 7 over 40.
Divide the two numbers to get the per second average. In this instance, it would equal out to roughly 5.71 feet per second.
Translate the number into a miles per hour equation. According to Calculate Me.com, "1 foot per second = 0.681818181818182 miles per hour" which you can use to figure it by hand or simply type it into the website's calculator. The above equation equals out to 3.893181818181818 miles per hour, or roughly 4 miles per hour.