Scan & Generate
QR Code Size Guide: Minimum Size, Print Guidelines & Best Practices
Getting QR code sizing right is critical — too small and it won't scan, too large and it wastes space. This guide covers minimum sizes, scanning distances, and print-ready best practices.
Why QR Code Size Matters
A QR code must be large enough for a smartphone camera to capture and decode it reliably. If the code is too small or the resolution is too low, scanners will fail — frustrating your users and wasting your print run.
The minimum scannable size depends on three factors: the amount of data encoded (more data = more modules = larger code needed), the scanning distance, and the print resolution.
Minimum QR Code Sizes
Here are recommended minimum sizes for common use cases:
| Use Case | Minimum Size | Scan Distance |
|---|---|---|
| Business card | 2 × 2 cm (0.8 in) | 10–15 cm |
| Product label | 2.5 × 2.5 cm (1 in) | 15–25 cm |
| A4 flyer / letter | 3 × 3 cm (1.2 in) | 25–40 cm |
| Poster (A3/A2) | 5 × 5 cm (2 in) | 50–100 cm |
| Banner / billboard | 15+ cm (6+ in) | 1–3 meters |
| Digital screen | 120 × 120 px | 15–30 cm |
Scanning Distance Formula
A common rule of thumb is the 10:1 ratio — the scanning distance should be no more than 10 times the width of the QR code. So a 3 cm QR code can be scanned from about 30 cm away.
More precisely:
QR code size = Scanning distance ÷ 10
If your poster will be viewed from 2 meters away, you need a QR code at least 20 cm wide. For a business card scanned at arm's length (~30 cm), 3 cm is sufficient.
Resolution and Print Quality
For print, always export QR codes at 300 DPI or higher. At 300 DPI, each module (the tiny black/white square) should be at least 2–3 pixels wide. Lower resolutions can cause modules to blur together, making the code unscannable.
- Vector formats (SVG, PDF) — best for print; scales to any size without quality loss
- PNG at 300+ DPI — good for print if generated at the final size
- JPEG — avoid for QR codes; compression artifacts can corrupt the code
Data Density and Module Count
The more data you encode, the more modules the QR code needs, and the larger it must be printed. Here's a rough guide:
- Short URL (under 50 chars) — Version 3 (29×29 modules), prints well at 2 cm
- Full URL with parameters (100+ chars) — Version 7+ (45×45 modules), needs at least 3 cm
- vCard with full contact info — Version 10+ (57×57 modules), needs at least 4 cm
- WiFi credentials — Version 5–7, prints well at 2.5 cm
Pro tip: Use a URL shortener to reduce the data in your QR code, which lets you print it smaller while keeping it scannable.
Quiet Zone (White Border)
Every QR code needs a quiet zone — a clear white border around all four sides. The QR code standard requires a minimum quiet zone of 4 modules wide. Without this border, scanners may not detect the code boundaries.
When placing a QR code in a design, never let other elements (text, images, borders) touch or overlap the quiet zone. Most QR code generators include this automatically, but check when embedding into designs.
Color and Contrast Tips
- Maintain a minimum contrast ratio of 4:1 between the dark modules and light background
- Dark modules on a light background works best (don't invert)
- Avoid transparency and gradient backgrounds behind the code
- Test on multiple devices before committing to a print run