How do you calculate projection distance?
Robert Miller
Published Feb 18, 2026
How do you calculate projection distance?
For any given projector, the width of the image (W) relative to the throw distance (D) is know as the throw ratio D/W or distance over width. So for example, the most common projector throw ratio is 2.0. This means that for each foot of image width, the projector needs to be 2 feet away or D/W = 2/1 = 2.0.
How far away does a projector need to be for a 72 inch screen?
Projection Distance
| 16:10 Aspect Ratio | ||
|---|---|---|
| Screen or image size | Projection distance (1) Wide to Tele | Offset from lens center (2) |
| 60 inches | 24 to 33 inches (61 to 84 cm) | 3.7 inches (9 cm) |
| 70 inches | 28 to 39 inches (72 to 99 cm) | 4.4 inches (11 cm) |
| 80 inches | 33 to 45 inches (83 to 113 cm) | 5 inches (13 cm) |
How far should a projector be from a 120 inch screen?
Projection Distance
| Screen or image size | Projection distance (1) Minimum to Maximum | Screw hole number (2) |
|---|---|---|
| 80 inches (203 cm) | 110 to 121 inches (281 to 306 cm) | 4 |
| 100 inches (254 cm) | 138 to 151 inches (351 to 383 cm) | 3 |
| 120 inches (305 cm) | 166 to 181 inches (422 to 461 inches) | 2 |
| 150 inches (381 cm) | 208 to 227 inches (529 to 577 cm) | 1 |
How far should a projector be from a 100 inch screen?
Projection Distance
| Screen or image size (1) | Projection distance (2) Wide to Tele |
|---|---|
| 60 inches (152.4 cm) | 69 to 113 inches (176 to 286 cm) |
| 80 inches (203.2 cm) | 93 to 150 inches (235 to 382 cm) |
| 100 inches (254 cm) | 116 to 188 inches (295 to 478 cm) |
| 120 inches (304.8 cm) | 139 to 226 inches (354 to 575 cm) |
How far away from the screen should a projector be?
We’re moving a bit closer to the screen. Short throw projectors need to be between 5 and 10 feet away from the screen, depending on how large of an image you want. Short throw projectors have a throw ratio between . 4 and 1.
How far should you sit from a 110 inch screen?
So, if the width of your TV is 55 inches, the minimum viewing distance should be 110 inches or around 9 feet, while the maximum distance should be 275 inches or no more than 23 feet. In short, the first row of recliners should be placed at least 9 feet away from the screen.
How high should a projector screen be from the floor?
24” to 36” inches
The screen height should be roughly one-third of the distance from the display to the seats in the media room. Place it 24” to 36” inches above the floor as the optimum vertical Viewing angle is in the range of 15 to 20 degrees.
What is the best distance between projector and screen?
The absolute “best” distance between the projector screen and room seating is hard to calculate. Instead, a general rule is that seats should be located a distance that is no less than double the width of the projected image, and no more than five times the width of the image (the furthest seat from the screen.)
How many lumens should a good projector have?
Projector brightness is measured in lumens. For home theater projectors where ambient light is kept to a minimum, you’ll need a minimum of 1500 lumens. For classrooms, conference rooms or rooms with windows, a projector with a minimum of 2500 lumens is best.
What is a good throw ratio for projectors?
Guide to Buying Short Throw and Ultra Short Throw Projectors
| Projector Type | Throw Ratio | Distance From Screen |
|---|---|---|
| Regular Projector | 1.5:1 + | 7.5 feet |
| Short Throw Projector | 0.38:1 – 1.4:1 | 3 feet |
| Ultra Short Throw Projector | 0.37:1 or less | 1.4 feet |
What height should I mount my projector?
We recommend that the bottom of the screen be between 24” and 36” inches off the floor. If you have multiple rows of seating, you may need to go a bit higher to keep clean sight-lines for people sitting behind the first row.
How close is too close to movie screen?
