Barco Throw Distance Calculator: How to Use It

This calculator works out the throw distance for a Barco projector: you enter the projector’s lens type (or its throw ratio) and the screen width you want, and you get the minimum and maximum distance the projector can sit from the screen. It also works in reverse—enter a room depth and screen width to see which lens fits. The math is simple: throw distance equals throw ratio times screen width, and the calculator handles the unit conversions and the two ends of a zoom lens’s range.

Formula

The core formula is Throw Distance = Throw Ratio × Screen Width. For a zoom lens, you have two ratios, so you get two distances:

• D_min = R_min × W (shortest distance, lens at wide-angle)
• D_max = R_max × W (longest distance, lens at telephoto)

Where:

• R_min and R_max are the throw ratio limits of the lens (unitless, e.g., 1.5–2.0:1)
• W is the screen width in meters (or feet, as long as you use the same unit for both)
• D is the distance from the front of the lens to the screen surface, in the same unit

Barco publishes these ratios in each projector’s datasheet, usually as a range like “1.5–2.0:1â€� for a standard zoom lens. If you have a fixed lens, the min and max are the same number.

Worked Example

Using the defaults from the calculator above—a lens with a throw ratio of 1.5 to 2.0 and a screen width of 3 meters:

1. Minimum distance: 1.5 × 3 = 4.5 m
2. Maximum distance: 2.0 × 3 = 6.0 m

So the projector must sit between 4.5 and 6.0 meters from the screen. If your room is deeper than 6 m, you need a longer-throw lens; if it’s shallower than 4.5 m, you need a shorter-throw lens.

Why Throw Distance Matters for Barco Projectors

Barco makes large-venue projectors for cinemas, auditoriums, and simulation installations. These are not home-theater pico projectors—they often use interchangeable lenses, and the lens you choose determines where the projector can physically be placed. Getting the throw distance wrong means either the image spills off the screen or the projector cannot fill the screen at all. Unlike a consumer projector with a built-in zoom, a Barco lens might have a limited zoom range (e.g., 1.5–2.0:1), so you must select the lens model that matches your room’s geometry. The calculator above gives you the usable range; you then compare it to your actual mounting position.

How to Choose the Right Lens

Barco’s lens naming convention usually includes the throw ratio range (for example, a lens labeled “0.84–1.02:1â€� is a short-throw lens). To choose correctly:

• Measure your screen width (not diagonal) in meters or feet.
• Measure the distance from the lens mounting point to the screen.
• Divide the distance by the screen width to get the required throw ratio.
• Pick a lens whose published ratio range includes that number.

For example, if the distance is 5 m and the screen is 3 m wide, you need a ratio of 5 ÷ 3 = 1.67. A lens with a 1.5–2.0 range works; a 0.84–1.02 lens does not.

Common Mistakes and Misconceptions

The most frequent error is using the screen diagonal instead of the width. Throw ratios are always based on width. A second mistake is ignoring the lens shift—Barco projectors often have vertical and horizontal lens shift, which moves the image without changing the throw distance, but some people confuse shift with zoom. Also, the throw distance is measured from the front of the lens, not the back of the projector or the ceiling mount. Finally, remember that the calculator gives the distance to the screen surface, not to the screen frame or the wall behind it. If you have a recessed screen, add the recess depth to your measured distance.

Limits of the Simple Formula

The formula assumes a flat screen and a lens with a linear throw ratio. In reality, Barco lenses have slight optical distortion, and the actual throw distance can vary by a few percent depending on focus and lens quality. For critical installations, Barco provides detailed CAD drawings and lens data sheets with exact distances for each screen size. The simple formula is accurate enough for initial planning and for checking whether a lens is in the right ballpark, but for a final installation you should consult the specific lens datasheet. Also, this calculator does not account for anamorphic lenses or 4:3 vs 16:9 aspect ratios—those change the effective width calculation.

Alternatives to Manual Calculation

Barco’s own website has a projector calculator tool for its current models, but it is model-specific and requires you to know the exact projector and lens. If you are working with an older or second-hand Barco unit, the datasheet PDF is often the only source. The simple ratio method here works for any projector, not just Barco—you can use it for a Christie, Sony, or any brand with a published throw ratio. For a quick estimate, you can also use the inverse: divide the room depth by the screen width to get the required ratio, then compare to the lens range.

Frequently Asked Questions

What is a throw ratio?

A throw ratio is the distance from the lens to the screen divided by the screen width. A ratio of 2.0 means the projector must sit 2 meters away for every 1 meter of screen width. It is a dimensionless number, so it works in any unit.

How do I find the throw ratio for my Barco projector?

Look at the lens barrel or the datasheet that came with the lens. Barco prints the ratio range on the lens itself (e.g., “1.5–2.0:1â€�). If you only have the projector model, search for the projector’s spec sheet, which lists compatible lenses and their ratios.

Can I use this calculator for a ceiling-mounted projector?

Yes, but measure the distance from the lens to the screen along the light path, not the straight vertical drop. If the projector is mounted at an angle, the throw distance is the diagonal distance from lens to screen center, not the horizontal distance from the wall.

What if my screen is measured in inches?

Convert the screen width to the same unit you use for the throw ratio. The calculator above uses meters, but you can use feet or inches as long as you divide the distance by the width in the same unit. For a quick conversion, 1 inch = 0.0254 m.

Does the throw distance change with zoom?

Yes. A zoom lens has a range of throw ratios, so the distance changes as you zoom. The calculator gives you the minimum and maximum for the lens’s range. You must physically place the projector within that range; you cannot exceed it.

Why does Barco list a throw ratio range instead of a single number?

Because most Barco lenses are zoom lenses. The range covers the shortest (wide-angle) to longest (telephoto) settings. Fixed lenses have a single ratio, but they are less common in large-venue projectors.

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in ratio | Throw ratio (min) | - | 1.5 | 0
in ratio_max | Throw ratio (max) | - | 2.0 | 0
in width | Screen width | m | 3 | 0
out dist_min | Min throw distance | m | ratio * width | 2
out dist_max | Max throw distance | m | ratio_max * width | 2