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 J7's 1.51:1 fixed lens.

Throw ratio, shortest

Throw ratio, longest

Image diagonal

inches

Screen shape

Lens to screen

4.01 m

13′ 2″

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 diagonal: 120″ (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)4.01 m from screen

Won't fitThe lens needs to be at least 4.01 m from the screen, plus about 35 cm for the chassis, so you need 4.36 m of room depth. Pick a smaller image or a shorter-throw lens.

Image

2.66 × 1.49 m

8′ 9″ × 4′ 11″

Lens can sit

4.01 m

13′ 2″

At 4.01 m

✓ Fills the screen at 1.51:1

fixed 1.51:1 lens

Show the numbers

Value	Metric	Imperial
Image width	2.66 m	8′ 9″
Image height	1.49 m	4′ 11″
Nearest lens position	4.01 m	13′ 2″
Furthest lens position	4.01 m	13′ 2″
Room depth needed (+35 cm chassis)	4.36 m	14′ 4″

Top-down view, to scale. A 120-inch 16:9 image is 2.66 m wide. A 1.51:1 lens must be 4.01 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.