A QR code that is too small will not scan, and a code that is too large wastes valuable space on your printed material. Getting the size right depends on three factors: the scanning distance, the density of the encoded data, and the print resolution. This guide covers the practical rules for every common scenario, from tiny business cards to massive billboards.
The 10:1 Rule
The most reliable rule of thumb is the 10:1 ratio: the maximum scanning distance should be no more than ten times the width of the QR code. A code printed at 3 cm wide scans reliably from about 30 cm away. A 30 cm code on a poster works from roughly 3 meters. A billboard-sized code at 1 meter wide can be scanned from about 10 meters. This ratio assumes standard data density and normal lighting conditions.
Minimum Sizes by Application
For business cards, the smallest practical size is 2 cm (about 0.8 inches) square. At this size, keep the encoded data short: a URL under 50 characters works well, but a full vCard with seven fields may produce a code too dense to scan reliably. Product packaging labels work well at 2.5 to 3 cm. Restaurant table tents and flyers should use at least 4 cm. Posters intended for reading from 1 to 2 meters need codes at least 10 to 15 cm wide. Exhibition banners viewed from across a room should use 20 to 30 cm codes.
Data Density Matters
A QR code encoding a 20-character URL has far fewer modules than one encoding a 200-character vCard. More modules means smaller individual squares, which means the code needs to be printed larger for the same scanning reliability. If your code looks very dense (many tiny squares packed tightly), increase the print size or reduce the amount of encoded data. Using a URL shortener is one of the most effective ways to reduce density.
Print Resolution
For printed materials, ensure your QR code is exported at a minimum of 300 DPI. Lower resolutions produce blurry module edges that confuse scanner algorithms, especially for dense codes. Vector formats (SVG) are ideal because they scale to any size without quality loss. Our generator produces PNG files at 560 pixels wide, which is sufficient for print sizes up to about 5 cm at 300 DPI. For larger prints, regenerate at a higher size or use an SVG export.
Quiet Zone
The white border around a QR code, called the quiet zone, is mandatory for reliable scanning. The specification requires a minimum of four modules of blank space on all sides. Never crop this border or place text, images, or other design elements directly against the code edge.
Related Tools
Generate codes for any data type: URLs, WiFi networks, contact cards, or plain text. For understanding damage tolerance, read about error correction levels.
Frequently Asked Questions
What is the absolute minimum QR code size?
About 1 cm (0.4 inches) for a code with minimal data and perfect printing conditions. In practice, 2 cm is the smallest size that scans reliably across different phone cameras and lighting conditions.
How big should a QR code be on a billboard?
For a billboard viewed from 10 meters, the code should be at least 1 meter wide. For highway billboards viewed at speed from 30+ meters, QR codes are generally impractical because drivers cannot safely scan while moving.
Does adding a logo affect the minimum size?
Yes. A center logo covers part of the code, relying on error correction to compensate. This means the remaining modules need to be clearly visible, so increase the print size by about 25 percent compared to a code without a logo.
What DPI should I use for printing QR codes?
300 DPI is the standard for most print materials. For high-quality packaging or small codes on luxury products, 600 DPI produces crisper edges. Screen displays at 72 or 96 DPI are fine because digital pixels are sharper than printed dots.
Can I make a QR code too big?
Not from a scanning perspective: larger codes scan from farther away. But an unnecessarily large code wastes space on your design. Match the size to the expected scanning distance using the 10:1 rule, then add a small margin for comfort.