The 10:1 Rule: Match Code Size to Scanning Distance
The single most useful formula for QR code sizing is the 10:1 distance-to-size ratio: the QR code's minimum side length should be at least 1/10th of the maximum distance from which it will be scanned.
- Scanning distance of 20 cm (business card held in hand) → minimum code size: 2 cm × 2 cm
- Scanning distance of 50 cm (flyer on a desk) → minimum code size: 5 cm × 5 cm
- Scanning distance of 1 m (poster on a wall) → minimum code size: 10 cm × 10 cm
- Scanning distance of 10 m (banner at an event) → minimum code size: 100 cm × 100 cm (1 m × 1 m)
This formula assumes good lighting, a clean print, and error correction level M or higher. At error correction level H (30% damage tolerance, used when adding a logo), increase the size by approximately 25% to compensate for the higher module density.
QR Code Size Chart by Material Type
| Material | Typical Scan Distance | Min Size (cm) | Recommended Size (cm) | Min Pixels (screen) |
|---|---|---|---|---|
| Business card | 20-30 cm | 2×2 cm | 2.5×2.5 cm | 150×150 px |
| Receipt / till slip | 15-25 cm | 1.5×1.5 cm | 2×2 cm | 120×120 px |
| Product label (small) | 15-20 cm | 1.5×1.5 cm | 2×2 cm | 150×150 px |
| Product packaging (handheld) | 20-30 cm | 2×2 cm | 3×3 cm | 200×200 px |
| Leaflet / flyer | 30-50 cm | 2.5×2.5 cm | 4×4 cm | 300×300 px |
| Magazine ad (half page) | 30-50 cm | 3×3 cm | 4×4 cm | 300×300 px |
| A5 tabletop card / tent card | 40-60 cm | 3×3 cm | 5×5 cm | 300×300 px |
| A4 poster (in-store) | 50-80 cm | 3.5×3.5 cm | 5×5 cm | 400×400 px |
| A3 / A2 poster | 80 cm-1.5 m | 5×5 cm | 8×8 cm | 500×500 px |
| Exhibition/event sign (2m high) | 1-2 m | 10×10 cm | 15×15 cm | 600×600 px |
| Window decal (shop front) | 1-3 m | 10×10 cm | 20×20 cm | N/A (printed) |
| Outdoor banner | 3-5 m | 30×30 cm | 50×50 cm | N/A (printed) |
| Billboard (roadside) | 5-15 m | 50×50 cm | 80×80 cm | N/A (printed) |
| Digital screen (monitor, kiosk) | 30-60 cm | 150×150 px | 250×250 px | 250×250 px |
| Presentation slide (projected) | 2-5 m | 300×300 px | 500×500 px | 500×500 px |
The Quiet Zone: Don't Neglect the White Border
Every QR code requires a quiet zone - a blank white margin around all four sides - for the scanner to distinguish the code from surrounding design elements. The minimum quiet zone width is 4 modules (the smallest square unit in the code). For most codes, this translates to approximately 4mm at the 2cm minimum print size, scaling proportionally with the code.
Do not allow any graphical elements, text, background colours, or bleed to intrude into the quiet zone. A QR code where the background pattern runs up to the code's edge will frequently fail to scan even though the code itself is correctly formed.
File Format Matters for Print
Always download your QR code as an SVG file (vector) for print applications. SVG files scale to any size - from 1cm to 10 metres - without any loss of quality or pixelation. PNG files have a fixed pixel resolution; a 500×500 px PNG printed at 30×30 cm will be blurry and may not scan reliably.
Our Free QR Code Generator outputs SVG by default for exactly this reason. For digital/screen use, PNG at the appropriate pixel dimensions is fine.
Data Density Also Affects Required Size
A QR code encoding a short URL (e.g. https://ab.cd/x - 16 characters) produces a lower-version, less-dense code that is easier to scan at smaller sizes. A QR code encoding a full paragraph of vCard contact data (200+ characters) produces a higher-version, denser code that requires a larger physical size to scan reliably at the same distance.
Practical tip: use a URL shortener for any content link that will be printed small. Keeping your linked URL short reduces code density and dramatically improves scan reliability at small print sizes. Even at 2cm × 2cm, a short URL code scans reliably; a dense vCard code at 2cm × 2cm may fail.