BenQ Projector Distance Calculator

Calculator Inputs

BenQ lens style

Calculation mode

Unit

Screen diagonal

Aspect width

Aspect height

Minimum throw ratio

Maximum throw ratio

Known lens distance

Rear clearance allowance

Safety margin percent

Screen bottom from floor

Vertical offset percent

Reset

Formula Used

Screen width = diagonal × aspect width ÷ square root of aspect width squared plus aspect height squared.

Screen height = diagonal × aspect height ÷ square root of aspect width squared plus aspect height squared.

Throw distance = screen width × throw ratio.

Screen width from distance = projector lens distance ÷ throw ratio.

Room depth = lens distance + rear clearance allowance. The safety margin then increases that depth by the entered percentage.

How to Use This Calculator

Select a BenQ lens style or choose the custom option.
Enter the throw ratio from your projector specification sheet when exact accuracy matters.
Choose whether to calculate distance from screen size or screen size from distance.
Enter the screen diagonal, aspect ratio, known distance, and clearance values.
Press Calculate. The result appears above the form and below the header.
Use the CSV or PDF button to save the planning result.

Example Data Table

Scenario	Screen	Aspect	Throw Ratio	Approximate Lens Distance
Gaming room	100 in diagonal	16:9	1.13 to 1.46	98.5 to 127.3 in
Short throw classroom	120 in diagonal	16:10	0.69 to 0.83	70.2 to 84.4 in
Conference room	90 in diagonal	16:9	1.49 to 1.64	116.9 to 128.6 in

Construction Planning With Projection Distance

A projector room works best when distance is planned before drilling. BenQ units can use different lenses, zoom ranges, and mounting clearances. This calculator helps convert those details into practical layout numbers. It starts with the screen diagonal and aspect ratio. Then it finds the actual image width. The width is the key value because throw ratio always uses image width, not diagonal size.

Why Distance Matters

Correct distance protects the image, the room, and the installer. A projector placed too close may create an image that is too large. A projector placed too far may fail to fill the screen. In construction work, this also affects conduit paths, ceiling plates, shelves, power outlets, and service access. A small planning error can move the mount several inches. That can leave visible patching, blocked ventilation, or awkward cable bends.

Using Throw Ratio

Throw ratio describes how many distance units are needed for each unit of image width. A 1.30 ratio means the lens should sit 1.30 feet away for every foot of screen width. Zoom lenses use a minimum and maximum ratio. The calculator uses both values and returns a safe placement range. You can enter a custom ratio from a BenQ manual for better accuracy. You can also compare screen sizes before choosing a final mount point.

Mounting Notes

Use the lens position, not the back of the projector, as the main distance point. Add a rear clearance allowance when checking total room depth. Leave space for ventilation, cables, tilt adjustment, and future service. Check ceiling height and screen bottom height before fixing brackets. Lens shift and keystone correction should solve small alignment issues only. They should not replace careful mounting.

Best Use

This tool is suitable for home theaters, classrooms, meeting rooms, shops, and temporary buildouts. It gives a planning estimate, not a structural approval. Always confirm the selected BenQ model sheet before final drilling. Measure the finished wall, trim, screen border, and ceiling surface. Recheck results after any screen change. Careful preparation saves time, prevents damage, and creates a cleaner projection installation. Document measured values on site, and keep them with the construction drawings for later repairs or equipment replacement work.

FAQs

What is projector throw ratio?

Throw ratio is lens distance divided by image width. It tells how far the projector lens must sit from the screen for a certain image width.

Does this calculator work for every BenQ model?

It works when you enter the correct throw ratio. Use the preset for planning only, and check the exact model specification before installation.

Should I measure from the wall or the lens?

Measure from the lens to the screen surface. Then add rear clearance to estimate total room depth or shelf space.

Why does zoom create a distance range?

Zoom changes image size without moving the projector. The minimum and maximum throw ratios create the closest and farthest lens positions.

Can I use feet, inches, centimeters, or meters?

Yes. Select the unit you want. The calculator converts values internally and returns results using the same selected unit.

What is rear clearance allowance?

Rear clearance is extra space behind the lens distance. It helps allow for projector depth, cable bends, ventilation, and maintenance access.

Is keystone correction included?

No. Keystone changes image geometry, not throw distance. Use it sparingly after placing the projector as accurately as possible.

Why should I add a safety margin?

A safety margin covers small measuring errors, trim, wall unevenness, brackets, and future adjustments before final drilling begins.