How far away will a QR code work?

A QR code scans reliably at a distance of roughly 10 times its width — a 2 cm code works at about 20 cm, a 25 cm poster code at about 2.5 metres, and a billboard code needs to be measured in tens of centimetres to metres wide. This '10x rule' is the standard sizing guideline for print.

In practice, also account for: lighting (dim bars need bigger codes), angle (codes flat on tables scan worse than eye-level ones), print contrast (dark on light scans best), and how much data is packed in (denser codes need more size). Modern phone cameras are forgiving, but the person standing at the back of the room isn't.

Our free size calculator does the maths from your scanning distance and tells you exactly how large to print.