The definition
throw ratio = lens-to-screen distance ÷ projected image width
A 0.5 ratio throws an image 10 ft wide from 5 ft away. A zoom lens has a range (for example 0.69–0.83), so the distance can vary within that range.
The golf-screen catch: the frame is wider than the screen
When a 16:9 projector fills a 4:3 screen, its image height matches the screen height and its width overhangs — the software masks the sides. So use the frame width, not the screen width:
| Screen | 16:9 frame width | 16:10 frame width |
|---|---|---|
| 10.5 × 8 ft (4:3) | 14.2 ft | 12.8 ft |
| 12 × 9 ft (4:3) | 16 ft | 14.4 ft |
| 8 × 8 ft (1:1) | 14.2 ft | 12.8 ft |
FOREference calculationFrame width = screen height × native aspect. Then distance = throw ratio × frame width.
Every projector's distances
The throw distance chart lists the distance for every projector we cover.
Figures marked as FOREference calculations show their working; product figures come from the sources on each product page. How we work