How to Use the Projector Screen Size Calculator
How big a picture your projector can display depends on the throw distance and the projector's throw ratio. Throw ratio is the throw distance divided by the screen width, and you can find it in almost any projector's spec sheet. This calculator takes your throw distance, throw ratio, and aspect ratio (16:9, 4:3, or 16:10) and calculates the screen's width, height, and diagonal size in inches.
At the same throw distance, a short-throw projector with a smaller throw ratio produces a larger screen, while a projector with a larger throw ratio needs more distance to reach the same screen size. When setting up a living room or home theater, it helps to measure the actual distance to the wall first, then use this calculator to check whether the screen size you want will actually fit the space.
Pick the aspect ratio that matches what you'll mostly watch. Most movies and streaming content use 16:9, older broadcast content uses 4:3, and some presentation or laptop content uses 16:10. These results are theoretical — always double-check against your projector's official throw distance table before final installation.
Frequently Asked Questions
Throw ratio is the throw distance divided by the screen width, and it's listed in the projector's spec sheet. A smaller throw ratio means a bigger screen at the same distance.
Most movies and streaming content use 16:9, older broadcast content uses 4:3, and some laptop or presentation screens use 16:10. Pick the ratio that matches what you'll mostly watch.