Relationship Between Club Head Speed and Ball Speed

Basically the calculation is your ball speed is 1.5 times faster than your swing speed. So, if you swing a club at 100mph, the maximum you can expect would 150 mph ball speed.

My local Trackman range does Ball speed and find distance quoted pretty much what I'd expect when using the practice widget. However if playing " a course" distances are all over the place ,drives nowhere as long and little chips for for ever