Projector Screen Size Calculator
Find how big a projected picture will be, given how far the projector sits from the screen. Pick a screen size that fits your room before you buy.
- Free
- Works offline after your first visit
- Saves on this device
- No sign-up
- Updated
How it works
The throw ratio is the distance from the projector to the screen divided by the picture width. So the width is the distance divided by the ratio.
The diagonal of a 16 by 9 picture is its width times about 1.15. Shorter throw ratios make bigger pictures from the same spot.
Worked example
A projector 10 ft from the wall with a throw ratio of 1.5 makes a picture 80 in wide, which is a 91.788 in diagonal in 16 by 9.
Questions
Where do I find the throw ratio?
It is in the projector's specification sheet, often listed as a range. Use the middle of the range if you are unsure.
Should the screen be the same size as the picture?
Yes, pick a screen at least as large as the picture size you calculate, with some room to spare at the edges.
Does room light matter?
Yes. A brighter room washes out the picture, so a darker room or a higher-brightness projector helps.
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