Projector Throw Calculator BenQ

Example Data Table

Formula Used

Screen width = diagonal × width ratio ÷ √(width ratio² + height ratio²)

Throw distance = screen width × throw ratio

Lens height = screen bottom height + screen height × vertical offset percentage + lens shift

Ceiling clearance = ceiling height − estimated lens height

How to Use This Calculator

Enter the planned screen diagonal first. Choose the screen aspect ratio. Add the minimum and maximum throw ratios from your projector manual. BenQ models use different lenses, so always confirm the exact ratio for your model. Add ceiling height, screen bottom height, vertical offset, and lens shift. Press the calculate button. The result appears above the form.

Projector Throw Planning Guide

Why Throw Distance Matters

Throw distance controls image size. It also affects room layout. A projector placed too close may create a smaller image. A projector placed too far may exceed the zoom range. This calculator helps you estimate a safe mounting zone before drilling, wiring, or buying a screen.

Understanding Throw Ratio

Throw ratio compares projector distance with screen width. A ratio of 1.2 means the projector sits 1.2 units away for every 1 unit of image width. Short throw models need less distance. Standard throw models need more depth.

Screen Size Planning

Screen diagonal alone is not enough. The actual width changes with the aspect ratio. A 120 inch 16:9 screen has a different width than a 120 inch 4:3 screen. This tool converts diagonal size into width and height automatically.

Lens Height and Offset

Projector placement is not only horizontal. Vertical offset also matters. Some projectors place the image above or below the lens center. Lens shift can correct small alignment issues. However, too much correction may reduce image quality.

Mounting Safety

Check ceiling clearance before mounting. Also allow space for cables, ventilation, and bracket depth. Heat needs room to escape. A tight mount may shorten projector life. Use the suggested throw as a planning value, not a final installation guarantee.

Best Practice

Measure the real wall, screen, and seating position. Test the image before final mounting. Use the projector manual for exact throw ratios. This calculator gives fast estimates for BenQ style planning and general room design.

FAQs

1. What is projector throw distance?

It is the distance between the projector lens and the screen surface. It decides how large the image appears.

2. What is throw ratio?

Throw ratio is projector distance divided by image width. It helps estimate mounting distance for a chosen screen size.

3. Can I use this for any BenQ projector?

Yes, for estimates. Enter the exact throw ratio from your model manual for better accuracy.

4. Why does aspect ratio matter?

Aspect ratio changes screen width and height. Throw distance depends mainly on screen width.

5. What is vertical offset?

Vertical offset shows where the image appears compared with the lens center. It affects mounting height.

6. Is zoom factor required?

Zoom factor helps understand flexibility. The main throw range still depends on minimum and maximum throw ratios.

7. Should I mount at the average throw distance?

The average throw is a useful planning point. Final placement should stay within the real zoom range.

8. Are results exact?

They are close estimates. Always verify with the official projector manual and a real room test.