June 1, 2026
QR Code Module Size: What It Is and Why It Matters
Every QR code is made of small black and white squares called modules. The size of these modules determines how large the QR code appears and how far away it can be scanned.
This guide explains module size and why it matters for QR code reliability.
What Is a Module?
A module is the smallest unit in a QR code grid. Each module is either black or white. The QR code's data, error correction, and structural patterns are all encoded as patterns of modules.
A QR code version 3 has 29 × 29 = 841 modules. Version 6 has 41 × 41 = 1681 modules.
Module Size vs QR Code Size
The total QR code size equals module size × number of modules.
Total QR size = Module size × Number of modules per side
Example:
- QR code with 29 modules (version 3)
- Module size = 1 mm
- Total QR size = 29 × 1 mm = 2.9 cm
Minimum Module Size for Printing
| Printing Method | Minimum Module Size | Notes |
|---|---|---|
| Laser printer | 0.2 mm (0.008 in) | Standard office printer |
| Inkjet printer | 0.25 mm (0.01 in) | May bleed at very small sizes |
| Commercial offset | 0.15 mm (0.006 in) | High precision |
| Screen print | 0.3 mm (0.012 in) | Ink spread consideration |
| Flexography | 0.3 mm (0.012 in) | Common for packaging |
| Digital press | 0.15 mm (0.006 in) | Modern digital printing |
Practical minimum: 0.3 mm (0.3 pt) module size for reliable scanning on most print methods.
Module Size by Scanning Distance
| Module Size | QR v3 Size | Max Scanning Distance | Best For |
|---|---|---|---|
| 0.3 mm | 8.7 mm | 3 cm | Micro QR on tiny parts |
| 0.5 mm | 14.5 mm | 5 cm | Small labels |
| 1 mm | 29 mm | 10 cm | Business cards |
| 2 mm | 58 mm | 20 cm | Product packaging |
| 5 mm | 145 mm | 50 cm | Flyers, menus |
| 1 cm | 29 cm | 1 m | Posters |
| 2 cm | 58 cm | 2 m | Indoor signs |
| 5 cm | 145 cm | 5 m | Outdoor signs |
Module Size Calculation
Formula
Module size (mm) = Scanning distance (mm) / 300
Examples
| Scanning Distance | Module Size | QR Code Size (v3) |
|---|---|---|
| 15 cm (business card) | 0.5 mm | 1.45 cm |
| 30 cm (flyer) | 1 mm | 2.9 cm |
| 1 m (poster) | 3.3 mm | 9.6 cm |
| 3 m (sign) | 10 mm | 29 cm |
| 10 m (billboard) | 33 mm | 96 cm |
Module Size and Print Resolution
For crisp QR codes, the print resolution must be high enough:
| Module Size | Min DPI | Print Quality |
|---|---|---|
| 1 mm | ~25 DPI | Very low |
| 0.5 mm | ~50 DPI | Low |
| 0.3 mm | ~85 DPI | Medium |
| 0.2 mm | ~127 DPI | Good |
| 0.15 mm | ~169 DPI | High |
Formula: Min DPI = 25.4 / module_size_in_mm
Why Module Size Matters
Scanner Resolution
Phone cameras have a minimum resolution requirement. Each module should cover at least 3-4 pixels on the camera sensor for reliable decoding.
Print Quality
Print defects like ink spread, misregistration, and paper fibers blur module edges. Larger modules are more tolerant of these defects.
Surface Curvature
On curved surfaces, modules distort. Larger modules are less affected by curvature distortion.
Testing Module Size
Quick Test
- Print your QR code at the intended size
- Place it at the expected scanning distance
- Try to scan with 3 different phones
- If any phone fails, increase the size by 20%
Professional Test
Use a module size test card with QR codes at decreasing module sizes to find the minimum reliable size for your specific printing and use case.
Creating QR Codes with Correct Module Size
Use a free QR code generator that outputs SVG:
- Enter your URL
- Download SVG
- Set the module size in your design software
Conclusion
Module size determines scan reliability. For print, aim for 0.3-0.5 mm minimum module size. For digital displays, size modules so the QR code occupies at least 10% of the screen width.
Create QR codes with precise module control — generate SVG QR codes and specify exact physical dimensions.