What is Projector Throw Ratio?

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Updated December 6, 2022

“What is projector throw ratio?” is a question that will pop up during projector installation. Another question is how long do projector lamps last? And, where exactly do you position the projector? There’s much more to know beyond the throw ratio. However, there are a few terms to know before fully understanding how a normal throw projector works or even what throw is. There is a range of projectors to choose from, but the best projectors have a short throw for high-quality results in smaller spaces.

To put it bluntly, the throw ratio helps you calculate the image size of your projector. This is not necessarily the adjustment calculation for zoom, this is the calculation of the foot of image width. In short, how far away your projector must be to present a nice picture without blur and give the viewer an enjoyable experience.  


  • 1.5:1 is a common projector throw ratio and means you’ll set your projector 7.5 feet away from the projection screen.
  • Understanding concepts like ambient light, keystone correction, and throw matter for projectors more than anything else, so keep researching.
  • Unless you’re using public engagement spaces, you probably don’t have a lot of room to work with and should consider investing in a short throw projector.

Why Throw Ratios Matter to You

Just like aspect ratio, throw ratio is crucial to deciding on projector screen size. Certain adjustments, like a keystone correction, can help you move your projections no matter the projector screen size. Keystone correction can’t help you if your projector’s throw can’t handle the distance, however.

Therefore, if you want precise projector placement, you’ll need to understand the throw ratio equation. Or, you can simply look at the projector specifications and use a calculator. 

Insider Tip

If you run into projector throw ratio problems, don’t hesitate to reach out to the manufacturer of your model for assistance.

Throw ratio allows you to choose an appropriate screen for an appropriately sized image. If a normal throw projector doesn’t fit your needs, try long-throw projection. “What is a long throw projector?” is a great question to start looking into things.

Exploring Throw Distance in Projectors

Aside from standard throw projectors, you have both long and short-throw projectors. Each has its application, and understanding the difference will help you invest wisely. There are other considerations to make when purchasing a standard projector, however.

Advances in technology mean that projector companies are continuously going the extra mile. You’ll see DLP and laser projectors now available If you’re thinking about using a smartboard, then the question, “Will any projector work with a smartboard?” is a worthy next query. 

How to Find Throw Distance

Finding throw distance usually is as easy as looking at the manual that projector companies always include with their packaging. You should be able to find it in the first few pages, although placement will vary.

If you have trouble finding the information, google your model or call the company that created it.

Breaking Down Throw Ratio Range

Throw ratio is crucial to understand for every standard projector model. This is especially true if you’re projecting on a larger screen and don’t have a lot of space to work with.

How to Calculate Throw Ratio

Having a smaller throw ratio means you can project larger images from a shorter distance. In order to find the ratio for your projector, you use this simple formula: TR = D/W, where:

  • TR means throw ratio
  • D means throw distance
  • W means image width


Projector technologies are prone to the same malfunctions as other electronics, so keep your projector installation instructions handy if you run into a problem.


Why does image brightness matter for projectors?

Projector lumens determine brightness, and a high-lumen projector will consistently outperform its counterparts. This is because the high-lumen image produced can easily overcome ambient light.

Are short-throw projectors more expensive than standard projectors?

A projector with a shorter throw distance will generally cost more. The good news is that these expensive projectors produce a higher-quality output image.

What size image can my standard projector produce?

Larger images require a higher projection distance. To get the widest image possible, use the throw ratio to calculate the preferred distance for your projector lens.

Is my room big enough for a projector?

Compact spaces can make finding space for a projector difficult. However, even limited space can be utilized by projection technology. Just shop for projector models made with little space in mind.

STAT: The PC monitor and projector market in Sweden is expected to grow larger than $260 million by 2021. (source)

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