A QR code that is too small will not scan. A QR code that is too large wastes valuable space on your design. Getting the size right depends on where the code will appear, how far away the scanner will be, and how much data the code contains. This guide gives you exact minimum sizes for every common use case.
What Is the Minimum QR Code Size?
The absolute minimum QR code size for reliable scanning is 2cm x 2cm (about 0.8 x 0.8 inches). At this size, the code works when scanned from approximately 15-20cm away — close enough for a business card or product label. However, this minimum assumes the QR code is relatively simple (a short URL with low error correction). More complex codes with longer data strings need to be larger because the individual modules (squares) become smaller and harder for cameras to resolve.
QR Code Size for Business Cards, Flyers, and Posters
For business cards, aim for 2-2.5cm x 2-2.5cm. This fits comfortably on a standard card while remaining scannable at arm's length. For flyers and handouts (A4/letter size), 3-4cm x 3-4cm works well because people typically hold them at about 30cm distance. For posters meant to be viewed from 1-2 meters away, your QR code should be at least 10cm x 10cm. For storefront windows or large-format signs scanned from 3+ meters, go to 20cm x 20cm or larger. The general rule: the scanning distance in centimeters divided by 10 gives you the minimum QR code size in centimeters.
How DPI and Print Resolution Affect QR Codes
When printing QR codes, use at least 300 DPI (dots per inch) to keep the edges of each module crisp and sharp. Lower resolution causes the squares to blur together, making the code harder to scan — especially at small sizes. Export your QR code as a PNG at the highest resolution your generator offers. If you are designing for large-format print (banners, billboards), you can lower the DPI to 150 because the viewing distance is much greater. Vector formats like SVG scale infinitely without quality loss, making them ideal for designs that will be resized.
The Distance-to-Size Ratio Explained
The industry-standard rule for QR code sizing is a 10:1 distance-to-size ratio. This means the QR code should be one-tenth the expected scanning distance. If someone will scan from 50cm away, your code needs to be at least 5cm wide. From 2 meters, at least 20cm. From 5 meters (large signage), at least 50cm. This ratio accounts for average smartphone camera resolution and typical lighting conditions. In poor lighting or when the code is behind glass, increase the size by 20-30% for a safety margin. Always test in real conditions before committing to a final print run.
Conclusion
Sizing your QR code correctly is the difference between a code that scans instantly and one that frustrates users. Use 2cm as your absolute minimum, apply the 10:1 distance-to-size ratio, print at 300 DPI, and always test before your final print run. Generate your QR code at qrcodes.gg and download it in high resolution, ready for any print size.