The 10:1 rule
The reliable rule of thumb is a 10:1 ratio of scan distance to code size. Divide the distance people will scan from by 10 to get the minimum width of the code.
For example, a code scanned from 2 metres away should be at least 20 cm wide. This gives phone cameras enough detail to lock on quickly.
Recommended sizes by use
- Business card: ~2 cm (scanned up close, in hand).
- Flyer / brochure: ~3–4 cm.
- Product packaging: ~2–3 cm depending on the surface.
- Table tent / menu: ~3–5 cm.
- Poster (1–2 m): ~10–20 cm.
- Storefront window (3–5 m): ~30–50 cm.
- Billboard (10 m+): ~1 m or larger.
Minimum size and margins
Never print a QR code smaller than about 2 cm × 2 cm, even for close scanning. Also keep the quiet zone — a clear margin of at least four modules around the code — or the extra size will not help.
Complex data (long links, vCards) creates a denser code that needs to be printed a little larger. Keep links short to keep the code simple. Generate yours with the QR code generator and export SVG for crisp scaling.