Where do I find throw ratio?

Check the projector datasheet or manual. Throw ratio is usually listed as a range when the lens has zoom (for example, 1.1–1.3:1).

Does this include lens shift or keystone?

The calculator models throw distance to fill the screen. Physical mounting may still need lens shift, ceiling height, and clearance; treat the result as a planning estimate.

Can I use it for ultra-short-throw projectors?

Yes, as long as you enter the correct throw ratio for your model. Ultra-short-throw units often use ratios below 1.0.

Projector Throw Calculator

Tune throw ratio and screen size, then visualize minimum and maximum projector placement.

Set screen size and throw ratio, then drag the projector in plan view along the throw line. The distance field and ratio stay in sync. Blue and purple floor markers show the min/max throw range.

Screen diagonal (inches)View modeThrow ratioThrow ratio minThrow ratio max

Screen width

2.44 m

Throw distance

4.14 m

Throw range

3.17–5.11 m (In range)

Throw distance (m)Throw distance (slider)

Drag the cyan projector along the room centerline. Throw distance updates live; min/max markers match your ratio range.

About Projector Throw Calculator

What this tool does

The Projector Throw Calculator shows where a projector must sit to fill a screen of a given width. Enter throw ratio, desired screen size, and room constraints to see a visual beam diagram.

It is useful when choosing a projector for a home theatre, classroom, or conference room, especially when mounting location and lens throw ratio are easy to get wrong on paper.

How to use it

1Enter your target screen width (or diagonal, depending on the fields shown).
2Set the projector throw ratio from the manufacturer specs (for example, 1.2:1).
3Adjust lens zoom or offset if the tool exposes those controls.
4Read the calculated throw distance and check it against your room depth and seating layout.
5Compare alternate screen sizes to see how much floor or ceiling space each option needs.

Frequently asked questions

Where do I find throw ratio?: Check the projector datasheet or manual. Throw ratio is usually listed as a range when the lens has zoom (for example, 1.1–1.3:1).
Does this include lens shift or keystone?: The calculator models throw distance to fill the screen. Physical mounting may still need lens shift, ceiling height, and clearance; treat the result as a planning estimate.
Can I use it for ultra-short-throw projectors?: Yes, as long as you enter the correct throw ratio for your model. Ultra-short-throw units often use ratios below 1.0.