Golf swing speeds are typically calculated using computerized technology. You can determine your approximate swing speed, however, using a formula based on the distance your golf balls travel. For each mile per hour of club speed, a golf ball travels about 2.3 yards, according to John Darling, PGA member instructor at Maderas Golf Club in California. This measurement can help you determine your swing speed.
Hit the driving range. Drive 10 golf balls. Note the number of yards each ball travels before initial ground contact. Do not measure rolling distance. Bring a partner along to spot your balls so you can concentrate on driving.
Disregard the extremes. Eliminating the longest and shortest drives ensures that undesirable factors such as wind are not skewing your average distance.
Find your average. Add the remaining drive distances and divide the total by eight. This will give you the average drive distance yardage.
Divide the average yardage by 2.3. This number represents your average club head speed in miles per hour, according to the book "Science and Golf III." If 195 is your average drive distance yardage, 84.7 mph is your approximate swing speed.