QR Code Size Guide: Best Dimensions for Print and Digital

The minimum QR code size is about 2 cm (0.8 in) for close-range scanning at 15-20 cm, and it grows with distance. A QR code's size is the width of the printed square, and the 10:1 rule sets it: divide the scanning distance by 10. The table below gives sizes for common uses, from business card codes to billboards.

What is the 10:1 rule for QR code size?

The 10:1 rule says a code's width should be at least one-tenth of the scanning distance. According to the Nielsen Norman Group, every 10 cm of distance adds 1 cm to the code's length and width. A poster scanned from 10 feet needs a code at least 1 foot across.

Treat 10:1 as the floor. A 7:1 or 8:1 ratio leaves margin for poor light and older phones.

What size should a QR code be for each use?

These sizes assume a short URL. As our own rule of thumb (not a published standard), add 20-30% when the code holds more data or carries a logo, and 10-15% on glossy stock. Use SVG for screens that resize.

What makes a QR code scan at a small size?

• Data density. Codes range from 21 x 21 modules (version 1) to 177 x 177 (version 40). A dynamic QR code with a short redirect URL keeps the module count low.
• Error correction. According to Denso Wave, four levels restore about 7% (L), 15% (M), 25% (Q) or 30% (H) of the data. Level H suits logos but makes the code denser.
• Quiet zone. The quiet zone is the blank border that tells a scanner where the code begins and ends. Denso Wave's guide requires four modules of margin on every side, and cropping it breaks scans.
• Contrast. Use dark modules on a light background, and aim for strong contrast (we use 4:1 as a rule of thumb).

How do you test a code before printing?

• Scan a printed proof at the real size, on the real material, from the real distance.
• Try an older budget phone as well as a new one, in bright and dim light.
• Export PNG, not JPEG, at 300 DPI or more for print. A 2 cm code at 300 DPI needs at least 236 x 236 pixels. QRCodeStack exports PNG up to 4096 x 4096 pixels, plus SVG or PDF for print; see how to create a QR code.
• Keep the code square and never stretch it.

The most common failures are a code squeezed too small, a long URL packed into it, and a cropped quiet zone.