Barcode Print Size Guide
The most common reason a printed barcode fails to scan is insufficient size. Use the calculator below to find the right dimensions for your scanning distance, then read the reference tables for GS1-specified minimums.
Minimum QR size
61.0 mm
In inches
2.40"
The 10:1 scanning rule
Industry guidance (ISO/IEC 18004) recommends that a QR code be printed at least 1/10th the size of the maximum scanning distance. A code scanned from 2 feet away (approximately 610 mm) should be at least 61 mm (about 2.4 inches) square.
This is a minimum. For low-contrast printing, worn surfaces, or older smartphone cameras, print larger — 1/8th or 1/6th of the scanning distance is safer.
Common distances reference
| Distance (ft) | Distance (m) | Min QR size (mm) | Min QR size (in) |
|---|---|---|---|
| 0.5 | 0.15 | 15.0 | 0.59" |
| 1 | 0.30 | 30.0 | 1.18" |
| 2 | 0.61 | 61.0 | 2.40" |
| 3 | 0.91 | 91.0 | 3.58" |
| 5 | 1.52 | 152.0 | 5.98" |
| 10 | 3.05 | 305.0 | 12.01" |
| 15 | 4.57 | 457.0 | 17.99" |
| 20 | 6.10 | 610.0 | 24.02" |
Minimum Size by Barcode Type
| Barcode Type | Min. Width | Min. Height | Magnification Range | Quiet Zone |
|---|---|---|---|---|
| UPC-A | 25.93 mm | 25.93 mm | 80–200% | 3.63 mm each side |
| EAN-13 | 31.35 mm | 22.85 mm | 80–200% | 3.63 mm left, 2.31 mm right |
| Code 128 | ~5 mm* | ~5 mm* | — | 10× narrow bar each side |
| Code 39 | ~8 mm* | ~5 mm* | — | 10× narrow bar each side |
| QR Code | ~10 × 10 mm | — | — | 4 modules each side |
* Code 128 and Code 39 have no GS1-mandated minimum; these are practical minimums for general-purpose scanners at close range. Adjust upward for handheld scanners at 0.5 m+.
Why Size Matters More Than Resolution
Barcode scanners — laser, CCD, and camera-based — read the ratio of bar widths, not absolute pixel counts. A barcode printed at 72 DPI can scan perfectly if it is large enough. A barcode printed at 300 DPI will fail if it is too small for the scanner's field of view.
That said, resolution matters for inkjet printing. Inkjet heads deposit ink that bleeds slightly into the label material (dot gain). At low DPI, dot gain widens the bars and can reduce the contrast ratios between bars and spaces. For inkjet printing, use 300 DPI or higher and test-scan before committing to a run.
Scanning Distance Guidelines
The rule of thumb is that a barcode should be at least 1/10 of the scanning distance wide. At 1 metre scanning distance, a QR code should be at least 100 mm (10 cm) wide. For warehouse rack labels scanned at 3 metres, aim for 300 mm (30 cm). For counter-top scanning at 20 cm, 20 mm wide is sufficient for most codes.