Projector throw calculator

Distance = throw ratio × image width. Enter the ratio from the spec sheet (one value for a fixed lens, two for a zoom), then the image size and shape. Distances are measured from the lens to the screen.

Set to the PowerLite 1785W's 1.04–1.26:1 zoom.

Throw ratio, shortest

Throw ratio, longest

Image diagonal

inches

Screen shape

Lens to screen

2.76–3.35 m

9′ 1″ to 11′ 0″

Image size

2.66 × 1.49 m

8′ 9″ × 4′ 11″

Or start from the distance

With the same lens and screen shape, how large an image does a given lens-to-screen distance give?

Lens to screen

metres

Image diagonals from 143″ to 174″ (16:9) at 4.00 m.

Image size120″

Screen shape

Room depth, screen to back wall4.2 m

Lens

Throw–:1

Projector position (or drag it)3.06 m from screen

FitsThe whole zoom range fits. The lens can go anywhere from 2.76 m to 3.35 m from the screen.

Image

2.66 × 1.49 m

8′ 9″ × 4′ 11″

Lens can sit

2.76–3.35 m

9′ 1″ to 11′ 0″

At 3.06 m

✓ Fills the screen at 1.15:1

zoom range 1.04–1.26:1 (1.21×)

Show the numbers

Value	Metric	Imperial
Image width	2.66 m	8′ 9″
Image height	1.49 m	4′ 11″
Nearest lens position	2.76 m	9′ 1″
Furthest lens position	3.35 m	11′ 0″
Room depth needed (+35 cm chassis)	3.11 m	10′ 3″

Top-down view, to scale. A 120-inch 16:9 image is 2.66 m wide. A 1.04–1.26:1 lens must be between 2.76 m and 3.35 m from the screen. The room is 4.2 m deep.

The plan above is to scale. Real lenses are not perfectly linear, so check the projection-distance table on the data sheet when the fit is tight.