

This is an easy-to-use image size and projection system calculator app that allows you to assign the range of BenQ projectors (and lenses where applicable) to a basic room diagram, adjust and calculate for room size and ceiling height, throw, aspect ratio, distance from projector to ceiling and floor, les shift, and various other parameters. Free online access and exportable results.
https://www.epson.com/alf_upload/landing/distance-calculator