Throw Distance Calculator

Use this calculator to estimate screen size from projector distance, or work backwards from your target image size to see how far back the projector should sit. It works for both mini and portable projectors, but remember: throw distance tells you fit, not brightness comfort.

To use this tool, enter your projector’s throw-ratio range from the brand’s official spec page, then either start from room distance or from the screen size you want.

ft
≈ 2.44 m

Aspect ratio

Choose the screen shape you want to calculate.

Estimated screen size range

Use your projector brand’s official throw-ratio range. If the lens has zoom, use both the minimum and maximum throw ratio values.

Image width range
64–80 in
(162.6–203.2 cm)
Image height range
36–45 in
(91.4–114.3 cm)
Diagonal range
73.4–91.8 in
(186.5–233.1 cm)

How to use it

Pull the throw-ratio range from the projector brand’s official spec page, then choose whether you want to start from room distance or target screen size.

Reality check

This tool estimates fit only. It does not tell you if the projector is bright enough for that image size in ambient light.

Mini vs portable

Mini projectors still work best in darker rooms and sensible screen sizes. Brighter portable projectors usually handle larger, more relaxed home setups better.

This calculator helps with fit, not brightness. A projector may be able to produce a 100-inch image in your room, but that does not automatically mean it will look bright enough in ambient light. Use it to check placement first, then compare brightness and room expectations before buying.

Next Key Pages

Mini Projector Buying Guide

Best Mini Projector For 2026

Portable Projector Buying Guide

Best Portable Projector For 2026