Projector aspect ratios explained
What projector aspect ratios mean and how each changes the image shape, with a table of width and height for a 100-inch screen in 16:9, 16:10, 2.40:1 and 4:3.
Aspect ratio is the width-to-height shape of the image. 16:9 is standard for TV and most projectors; 16:10 suits business and data; 2.40:1 is cinemascope for movies; 4:3 is the old square format. At the same 100-inch diagonal, a wider ratio means a wider, shorter image.
A projector’s native aspect ratio is fixed by its chip, though it can show other ratios with black bars. Most home projectors are 16:9. The table shows how the width and height of a 100-inch diagonal change with the ratio — handy for sizing a wall or matching a screen.
Image size by aspect ratio (100-inch diagonal)
| Aspect ratio | Width | Height |
|---|---|---|
| 4:3 | 80″ | 60″ |
| 16:10 | 85″ | 53″ |
| 16:9 | 87″ | 49″ |
| 2.40:1 | 92″ | 38″ |
Frequently asked questions
Related guides
Projector screen size guide
A screen's "size" is its diagonal, but placement depends on width. For a 16:9 screen, width = diagonal × 0.872 and height = diagonal × 0.490. So a 100-inch screen is 87 inches (221 cm) wide and 49 inches (124 cm) tall.
GuidesProjector viewing distance
A common guide is to sit about 1.2 to 2 times the screen WIDTH away. For a 100-inch 16:9 screen (87 inches / 7.3 ft wide) that is roughly 9 to 15 feet. Closer is more immersive (THX); further is more relaxed (SMPTE).
GuidesTrue 4K vs pixel-shift 4K
Native 4K projectors put 8.3 million real pixels on screen; pixel-shift (XPR) projectors flash a 1080p or 2.7K chip 2-4 times per frame to approximate 4K. Native is slightly sharper on fine detail but costs much more; pixel-shift looks 4K to most eyes at normal viewing distance and covers nearly all affordable "4K" projectors.
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