What to consider before you buy
Your seat is one of the biggest influencers when deciding screen height. Many change the seat to improve the overall comfort for long rides. While others simply need to improve their ability to comfortably reach the ground on those infrequent stops around town.
Whatever the reason to make a change in your seat remember the relationship to the screen will also be affected. Make sure to acquire and install your seat prior to checking for your screen height.
Handlebars have many different configurations. The main thing to remember is that they may adjust your riding position forward or backwards to the windshield and/or Fairing, in turn changing your perspective of the road ahead and determining your view through or over the screen.
If your ultimate goal is to look over the screen comfortably and you will be spending some time with a passenger, then you have one more thing to consider before choosing your screen height. A passenger’s weight will lower the tail end of the bike making the perfect screen for the rider cut right into his field of view. Many adjust the rear suspension to compensate for the added weight so when reviewing for screen make sure those adjustments are dialed in and your position relative to the top edge of your new screen is set comfortably.
With all of the above completed you are now ready to choose the correct height.