QR code · (modules + 8) × module size
QR code print size
Choosing a physical size from module count, scan distance and surface.
Key facts
| Formula | (modules + 8) × module size |
|---|---|
| Close phone scan | About 2 cm wide minimum |
| Poster viewing | Larger than the 10:1 distance rule suggests |
| Contrast | Dark modules on light background |
| Surface | Matte beats gloss under glare |
| Minimum module | About 0.3–0.4 mm for print |
Work backward from the scan
Start with how far away the code will be read. A phone at 30 cm needs far less symbol than a code read across a room. Multiply the module count plus eight (the quiet zone on both sides) by the module size to get the printed width. If that number is too large for the layout, reduce the payload or the error-correction level rather than shrinking modules below the practical floor.
Print quality beats size
A crisp 2 cm code scans better than a blurry 5 cm one. Use vector output where possible, avoid scaling raster images, keep edges sharp and choose matte stock. For outdoor use, laminate or use UV-resistant ink; fading quietly kills codes that once worked.
Frequently asked questions
How big should a QR code be for a poster?
Size it so a phone at the expected viewing distance can fill a useful part of the frame. For a wall poster read from 2–3 m, codes are usually at least 10–15 cm wide.
Does a bigger code always scan better?
Up to a point. Beyond the camera's focus and framing limits, a larger code can be harder to capture whole. Contrast and sharpness matter more.
Can I print in color?
Yes, if the dark modules stay dark and the light modules stay light in luminance. Avoid red-on-green combinations that differ in hue but not brightness.