Projectors throw around a lot of different terms in their marketing, whether they’re shouting about their upscaling abilities, HDR features, or light source technology. If you’re choosing between the best projectors on the market, though, throw ratio should be the first spec you check. After all, you can spend thousands on a high-end thrower and never see any of that quality if you don’t have enough space for it to work its magic.
A projector throw ratio describes how many feet you will need to place between your device's lens and the screen to achieve one foot of screen width.
That’s what a projector’s throw ratio tells you - how much space you’ll need to achieve a desired image size. Put simply, it’s a calculation of distance (how much space you have between your screen and the lens) and width (the horizontal size of your image), all measured in feet. In a spec sheet, this will be represented as a range set against a ratio of 1.
For example, the XGIMI Horizon Ultra has a throw ratio of 1.2-1.5:1. That means that for every 1ft of screen width, you’ll need 1.2-1.5ft of distance between the screen and the lens. To find the right projector for your space, you’ll need to know how much space you have to play with and how big you want your screen to be.
Throw Ratio = Distance / Width
Using this calculation will provide you with a number that you can match against projector specs to make sure you’re getting the right lens. It’s important to note, however, that this ‘width’ figure is measured in feet as well as everything else. That means we need to do a few conversions, as screen sizes are usually measured both diagonally and in inches. You’ll need to find the actual width of your desired screen size (a 120-inch diagonal screen has a width of 105 inches when set at its most common 16:9 dimension) and then convert it to feet (105 inches is 8.75ft).
If you have a distance of 12 feet between the spot you’d like to place your projector and your screen, and you know you want a 120-inch display, then dividing the distance by the width will give you your optimum projector throw ratio.
12 / 8.75 = 1.3
That means any projector with a throw ratio that encompasses 1.3:1 will be suitable for your needs. The Horizon Ultra above has a throw ratio of 1.2-1.5, and so will be compatible.
Like all equations, this goes both ways as well. You can use the calculation to work out how big your picture will be with a projector of a certain ratio, or how much space you need for your desired screen size using a projector you already have your eye on. Just use Distance = Throw Ratio X Width for the former and Width = Distance x Throw Ratio for the latter.
Using the optimal throw ratio for your projector will keep your picture focused and free from distortion, while being positioned to give you the biggest picture possible. Most projectors offer a throw ratio of between 1.2 and 2.0:1, but if you’re working with a smaller space it’s worth exploring short-throw options.
These projectors have throw ratios that often drop below 1, like the BenQ X300G which carries a range of between 0.69 - 0.83:1. These models can project at much closer distances, so you’ll be able to get a 120-inch screen with just 6ft of distance between the screen and the lens (0.69 x 8.75 = 6).
We’re rounding up all the best 4K projectors to fit any space, as well as the best PS5 projectors for more of a console focus. Or, if you’re taking this show on the road, check out the best portable projectors on the market.
