By definition, the throw ratio is the distance from projector to screen divided by the width of the image. The throw ratio spec for any projector assumes you're using the full width of the native resolution, which isn't true for many home golf simulators.The best position for the projector will usually be roughly 4 feet behind the tee location, which makes the distance easy enough to figure out. However, the width of the simulator is a limiting factor, and thus you probably use a 16:9 or 16:10 projector to project a 4:3 image. In this case, you won't be using the projector's full image width, and for easier calculation we suggest you choose the right throw ratio using the modified formula to calculate with distance and height.
Using the full width of the projector (4:3 projector to project a 4:3 image):
-Throw ratio=Distance / Width
Not using the full width of the projector (16:9 or 16:10 projector and adjusting the image to a 4:3 ratio):
-For a 16:9 projector, choose a projector with a throw ratio=0.5625 x Distance / Height
-For a 16:10 projector, choose a projector with a throw ratio=0.625 x Distance / Height