Calculate the throw distance, screen size, and throw ratio for an Acer projector, converting between projector distance and image dimensions for any aspect ratio.
Acer Projection Formula
An Acer projector calculator works from the throw ratio, which links how far the projector sits from the screen to the width of the image it produces. The throw ratio is the throw distance divided by the image width:
TR = D / W
Rearranging that relationship gives the two other things you usually want to find, the throw distance and the image width:
D = TR * W
W = D / TR
Projectors and screens are sold by diagonal size, but the throw ratio uses image width, so the calculator converts between the two using the aspect ratio. For an aspect ratio of a:b and a diagonal of Diag, the width and height are:
W = Diag * a / sqrt(a^2 + b^2)
H = Diag * b / sqrt(a^2 + b^2)
- TR = throw ratio of the projector, a single number with no units (a 1.2 throw ratio is written 1.2:1)
- D = throw distance, the straight line distance from the lens to the screen
- W = image width, the horizontal size of the projected picture
- H = image height, the vertical size of the projected picture
- Diag = screen diagonal, the size a screen or projector is normally rated by
- a, b = the two numbers of the aspect ratio, such as 16 and 9 for a 16:9 screen
The solve-for selector decides which formula runs. Choosing screen size uses W = D / TR, then converts the width to a diagonal. Choosing throw distance uses D = TR * W after turning the diagonal into a width. Choosing throw ratio divides your measured distance by the image width to give TR. The aspect ratio selector sets a and b, and the distance unit selector lets you enter feet, inches, meters, or centimeters while the screen size stays in diagonal inches.
Acer Throw Ratios and Screen Distances
The throw ratio printed on an Acer spec sheet tells you which group a model falls into. Use it to estimate how much space you need before you measure.
| Projector type | Typical throw ratio | Distance for a 100 in image width |
|---|---|---|
| Ultra short throw | 0.25 to 0.4 | 25 to 40 in |
| Short throw | 0.5 to 0.9 | 50 to 90 in |
| Standard | 1.1 to 1.5 | 110 to 150 in |
| Standard long | 1.5 to 2.0 | 150 to 200 in |
The next table shows the throw distance for common 16:9 screen sizes at two standard throw ratios, so you can sanity check the calculator against a familiar setup.
| Screen diagonal (16:9) | Image width | Distance at 1.2 throw ratio | Distance at 1.5 throw ratio |
|---|---|---|---|
| 80 in | 69.7 in | 7.0 ft | 8.7 ft |
| 100 in | 87.2 in | 8.7 ft | 10.9 ft |
| 120 in | 104.6 in | 10.5 ft | 13.1 ft |
| 150 in | 130.7 in | 13.1 ft | 16.3 ft |
Example Problems
Example 1. Your Acer projector has a 1.2 throw ratio and you can mount it 10 feet from the wall. Set solve-for to screen size, choose 16:9, enter a throw distance of 10 feet, and enter a throw ratio of 1.2. The throw distance is 120 inches, so the image width is 120 / 1.2 = 100 inches. Dividing 100 by the 16:9 width factor of 0.8716 gives a diagonal of about 114.7 inches, with a height near 56.3 inches.
Example 2. You want a 100 inch 16:9 screen and your Acer model lists a 1.5 throw ratio. Set solve-for to throw distance, choose 16:9, enter 100 for the diagonal, and enter 1.5 for the throw ratio. The image width is 100 * 0.8716 = 87.2 inches, so the throw distance is 1.5 * 87.2 = 130.7 inches, or about 10.9 feet from the lens to the screen.
Frequently Asked Questions
What is the throw ratio on an Acer projector? The throw ratio is the distance from the lens to the screen divided by the width of the image. A 1.2 throw ratio means the projector needs 1.2 feet of distance for every 1 foot of image width. Acer lists this number, sometimes as a range, in the specifications for each model. A smaller number lets you fill a large screen from closer in.
How do I find my projector throw ratio if it is not listed? Project an image, measure the throw distance from the lens to the screen and the width of the picture in the same units, then divide the distance by the width. Set the calculator to solve for throw ratio, enter both measurements, and it returns the same value. Keep both numbers in matching units so the ratio comes out unitless.
Does the screen aspect ratio change the throw distance? Yes, because the throw ratio is based on image width, not the diagonal. A 16:9 and a 4:3 screen with the same diagonal have different widths, so they need different throw distances at the same throw ratio. Set the aspect ratio in the calculator before solving so the width is taken from the correct shape.
