Start with how far away people will scan
A business card is held close to the camera. A poster or window sign may be scanned from several feet away. As viewing distance increases, the physical QR must also increase.
A commonly used planning rule is roughly a 10:1 relationship between scanning distance and code size, followed by real-world testing.
Close-range printed materials
For cards, labels, menus, and hand-held flyers, around 2–2.5 cm is a practical starting range rather than a guarantee. Dense codes, imperfect printing, or older cameras may require more space.
Do not measure only the dark pattern. Include the empty quiet zone around it in your layout.
- Business cards: protect a clean dedicated area
- Labels: avoid curvature and seams
- Menus: account for dim light and lamination
Posters, windows, and signs
Large materials tempt designers to leave the QR surprisingly small. Test the code from the distance where a person will naturally stand, not from arm’s length during design review.
Placement height, safe stopping space, glare, and camera angle can matter as much as the nominal dimensions.
Long URLs make denser QR patterns
More encoded characters generally require more modules. At the same printed size, each individual module becomes smaller and harder for a camera to resolve.
Use a concise stable URL on a domain you trust. Do not use an unknown shortener merely to reduce density for a permanent project.
Proof at final size
Export SVG when possible, place it at the intended dimensions, print with the real material and finish, then scan from multiple distances and phones.
The proof is the only reliable answer for a specific combination of URL, design, printer, substrate, and environment.