The 10:1 Sizing Principle
The most critical factor in QR code scannability is the relationship between the code's physical size and the distance of the person scanning it. As a general rule of thumb, maintain a 10:1 ratio.
Following this ensures that the camera's sensor can resolve the individual modules (the dots) of the QR code with enough clarity to decode the data.
Industry Standard Dimensions
While the 10:1 rule is a great starting point, specific mediums have established standards that guarantee a high success rate.
| Medium | Typical Distance | Minimum Size |
|---|---|---|
| Business Cards | 4 – 6" | 0.8 x 0.8" (2 x 2 cm) |
| Product Packaging | 12" | 1.0 x 1.0" (2.5 x 2.5 cm) |
| Magazines / Flyers | 18" | 1.25 x 1.25" (3 x 3 cm) |
| Wall Posters | 3 – 5 ft | 3.0 x 3.0" (7.5 x 7.5 cm) |
Resolution & Contrast
Size isn't the only factor. For print, always use vector formats (like SVG) or high-resolution bitmaps (at least 300 DPI). Low-resolution images will blur at small sizes, making them impossible to scan.
Contrast Requirements
Always maintain a high contrast ratio between the foreground (dots) and the background. Dark colors on light backgrounds are the most reliable. If you use a custom brand color, ensure it's dark enough to be distinguished from the white space.