QR Code Size, Ratio & Print Quality Standards
The definitive engineering guide to QR code physical dimensions, the 10:1 scanning ratio, error correction overhead, and commercial print preparation.
1. The 10:1 Distance-to-Size Formula
The standard optical rule is QR Width = Scan Distance ÷ 10. For example, a restaurant menu scanned from 30 cm requires at least a 3 cm width. A billboard scanned from 15 meters requires a 1.5-meter QR code.
2. Minimum Absolute Dimensions
Never print a QR code smaller than 20 mm x 20 mm (0.8 x 0.8 inches). For dense payloads such as vCards or Wi-Fi credentials, the minimum size increases to 35 mm x 35 mm (1.4 inches).
3. The 4-Module Quiet Zone
ISO/IEC 18004 specifies a mandatory blank margin of at least 4 module widths around all four edges of the symbol with zero graphics or background patterns.
4. SVG Vectors vs 300+ DPI Raster
Always prioritize scalable vector graphics (SVG) for print workflows to ensure mathematically infinite sharpness with zero pixelation.