TThrowCalc
Calculator

Projector screen size calculator

Enter your throw distance and projector throw ratio to find the largest 16:9 screen that fits. Free calculator with a distance-to-screen-size reference table.

Calculator

The biggest screen you can use is set by your throw distance ÷ throw ratio. As a rule of thumb, screen width = throw distance ÷ throw ratio, so a 1.2 throw-ratio projector 10 ft back fills about a 115-inch 16:9 screen. Enter your numbers below for the exact maximum.

Max screen size by throw distance

Throw distanceUST (0.5)Standard (1.0)Long (1.5)
8 ft22011073
10 ft27513892
12 ft300165110
15 ft300207138
20 ft300275184

How screen size and throw distance relate

A projector’s throw ratio is the throw distance divided by the image width, so the image width you can achieve is the throw distance divided by the ratio. A lower ratio (short- and ultra-short-throw) fills a bigger screen from the same distance, which is why UST projectors can sit inches from the wall. The result here is the maximum at your minimum ratio — zoom in to a smaller image any time.

Need the distance for a fixed screen instead? Use the throw distance calculator.

Find your maximum screen size

Find it on the projector’s spec page (e.g. 1.2 standard, 0.25 ultra-short-throw).

Up to a 115″ screen

100″ × 56″ image

Frequently asked questions

At a 1.2 throw ratio, 10 ft fills about a 115-inch 16:9 screen; a 1.5 ratio gives about 92 inches and a 0.5 (UST) ratio about 275 inches.