Projector Distance Calculator BenQ

Calculator Inputs

Use exact values from the projector manual for final construction. Presets are planning aids only.

Projector preset

Screen diagonal

Unit

Aspect width

Aspect height

Minimum throw ratio

Maximum throw ratio

Chosen mount distance

Room depth

Rear clearance

Seating distance

Screen bottom height

Ceiling height

Vertical lens offset percent

Border allowance per side

Example Data Table

Screen Diagonal	Aspect Ratio	Throw Ratio	Screen Width	Throw Distance Range	Use Case
100 in	16:9	1.15 - 1.50	87.16 in	100.23 - 130.74 in	Home room planning
120 in	16:9	1.15 - 1.50	104.59 in	120.28 - 156.88 in	Media wall layout
150 in	16:10	1.96 - 2.15	127.20 in	249.31 - 273.48 in	Meeting hall setup
80 in	4:3	0.69 - 0.83	64.00 in	44.16 - 53.12 in	Short throw room

Formula Used

Screen width: diagonal × aspect width ÷ √(aspect width² + aspect height²)

Screen height: diagonal × aspect height ÷ √(aspect width² + aspect height²)

Minimum throw distance: screen width × minimum throw ratio

Maximum throw distance: screen width × maximum throw ratio

Zoom ratio: maximum throw ratio ÷ minimum throw ratio

Lens height: screen bottom + half screen height + vertical offset adjustment

Available room depth: room depth - rear clearance

How to Use This Calculator

Enter the screen diagonal and select the working unit.
Enter the screen aspect ratio, such as 16:9 or 16:10.
Select a preset or choose custom throw ratios.
Enter the chosen mount distance from lens to screen.
Add room depth, seating distance, clearance, and height values.
Press Calculate and review the result above the form.
Use CSV for spreadsheet records.
Use PDF for installer notes or client review.

Construction Planning Guide

A projector distance plan should start before drilling begins. The screen size, throw ratio, and room depth must agree. BenQ style projectors often use different optical ranges. Therefore, the exact model ratio should always be checked. This calculator keeps the ratio visible. It also keeps custom values open.

Screen Geometry

The diagonal screen size is not enough by itself. The aspect ratio converts that diagonal into width and height. A 16 by 9 screen is wider than a 4 by 3 screen. The throw distance is then based on width. This is why two screens with equal diagonals can need different mount locations.

Throw Range

Throw ratio means distance divided by image width. A lower ratio places the projector closer. A higher ratio places it farther away. Zoom gives a usable distance band. The shortest throw normally creates the widest image. The longest throw normally creates the smallest image from the same location.

Mounting Checks

The tool compares your chosen mount distance with the calculated range. It can also compare room depth, rear clearance, ceiling height, and vertical offset. These checks reduce surprises during ceiling bracket layout. They also help estimate pole length and cable path before installation starts.

Practical Notes

Always leave service clearance around the projector. Keep ventilation open. Avoid placing the lens where people, doors, or beams will block the light path. Check keystone limits only as a backup. Physical alignment usually gives a cleaner image. Measure the finished screen frame, not only the advertised diagonal.

Use on Site

Enter the planned diagonal, aspect ratio, and throw ratio. Pick a preset only for early planning. Replace it with the exact manual value before final mounting. Add room depth, seating distance, screen bottom height, and ceiling height. Then calculate. Use the CSV file for site records. Use the PDF for client notes or installer handoff. Recalculate when the screen, model, or bracket changes.

Accuracy Limits

Manufacturer tables may round distance values. Lenses also have tolerance. Wall surfaces, screen borders, and bracket plates can change the final mark. Treat this result as a planning estimate. Confirm with a test projection before fixing anchors. Record the final distance after focusing. That note helps future maintenance on site.

FAQs

What is throw ratio?

Throw ratio is the projector distance divided by active image width. It tells how far the projector lens should sit from the screen for a chosen image size.

Can I use the preset values for final mounting?

Use presets for early planning only. Always check the exact BenQ model manual before drilling, because throw ratio, offset, and lens behavior can vary by model.

Why does aspect ratio matter?

The diagonal alone does not define screen width. A wider aspect ratio creates more width from the same diagonal, which changes the required throw distance.

What is vertical lens offset?

Vertical lens offset estimates how far the lens center sits above or below the screen center. It helps plan ceiling drop and bracket height.

Does this calculator include keystone correction?

No. Keystone correction changes the image digitally. This calculator focuses on physical placement, which is usually better for image clarity and construction accuracy.

What does room depth check mean?

Room depth check compares available space with the minimum throw distance. Rear clearance is subtracted so the projector has space for ventilation and cables.

Why is screen frame size shown?

Throw distance uses active image width. Frame size helps construction planning because brackets, walls, trims, and screen borders need real installation space.

Can I download the results?

Yes. Use CSV for spreadsheet work. Use PDF for installation notes, quotes, or client records after calculating the result.