Your golf club swing speed is the biggest factor in how far you hit the golf ball. You don't have to be a big, muscular person to have a high swing speed--although it doesn't hurt. Good form and flexibility are the keys to a fast swing speed. Many golf shops have equipment which can measure your swing speed, but you can also estimate it.
Visit a golf range and hit a number of balls using your driver. Make a list of the distance you are achieving with your drives. There are a number of factors that can affect your distance, besides swing speed, so when trying to determine the swing speed, use the distances of drives that feel good and achieve the best distances.
Average the distance of your drives by adding together your best ten drives and dividing by ten. Subtract 5 percent to account for the roll to determine your carry. For an example, we will assume 210 yards as an average carry, which is about the average of an amateur golfer.
Divide the carry distance by 1.75 to determine the ball speed. An average of 210 yards of carry will result in an estimated ball speed of 120 miles per hour.
Divide your estimated ball speed by the "smash factor" of 1.5. This will result in your estimated swing speed. A golfer with a 210 carry distance on drives has an estimated swing speed of 80 mph.
An additional formula that is often used for estimating is that every 2.3 yards of carry is equal to one mile per hour of swing speed. Using the above number, the formula would be 210 divided by 2.3. This results in a swing speed of about 91 miles per hour. The PGA estimates the average golfer's driving distance at 212 yards and swing speed at 80-85 mph. Therefore, it is clear that the first formula is most accurate for estimating.