Distance and Lens Decide the Image

The size of a projected image is determined before you even turn the projector on: throw distance divided by the lens throw ratio gives the image width, and the aspect ratio fills in the height. This projector screen size calculator converts those numbers into the diagonal you actually shop by.

The Zoom Range Gives You Room

Most projectors zoom, so a fixed mount position still offers a range of image sizes. Enter the lens's minimum and maximum throw ratios and you'll see the smallest and largest diagonals available from that spot — essential before drilling mounting holes.

Sizing the Room Around the Screen

A good home theater places seating at 1.2 to 2.4 screen heights. The seating estimate closes the loop: from your chosen mount position, the calculator tells you both how big the image will be and where the best seats are.