A QR code on a business card, flyer, and poster cannot use the same size. The right size depends on scanning distance, code density, print quality, and contrast.
A QR code can be technically correct and still scan badly in print. The most common reason is simple: it is too small for the distance people will scan it from.
A business card, flyer, and poster all need different sizing. There is no single universal number that solves every case. There is, however, a practical way to think about it.
Start with the scanning distance
For a printed QR code, distance matters most:
- a business card is scanned up close,
- a flyer is held in the hand,
- a wall poster is scanned from farther away,
- a shop window or sign may be farther still,
- a billboard is a separate case and needs a much larger code.
The greater the distance, the larger the QR code must be. This is not only about the outside size, but also about the size of the individual modules, the small squares inside the code.
Practical starting sizes
Treat these as starting points, not strict rules:
Business card: about 20-25 mm, if the code contains a short link or vCard and has strong contrast.
Flyer or brochure: about 30-40 mm.
Poster on a noticeboard: at least 50-70 mm, depending on distance.
Shop window or sign: often 100 mm or more.
Large surfaces: test in the real environment, not only on a monitor.
If the code is dense, colored, printed on glossy material, or scanned from an angle, make it larger.
The quiet zone counts too
A QR code needs empty space around it. This is called the quiet zone. DENSO WAVE says a QR code requires a four-module quiet zone on every side. This margin is not decoration. It is part of readability.
When designing print material, do not count only the square pattern. Count the clear space around it too.
A typical mistake:
- The designer places the QR code into a small area.
- It is reduced until it "fits".
- There is too little white space around it.
- It looks fine on screen, but scans poorly after printing.
Less data creates a simpler pattern
Size is not the only factor. The amount of data matters too. A short URL creates a simpler QR pattern. A long URL with many parameters creates a denser pattern.
If the code must be small, simplify the content:
- use a shorter URL,
- remove unnecessary parameters,
- put long text on a web page instead,
- for vCard, include only useful fields.
Why SVG is better for printed QR codes
For print, use SVG whenever you can. SVG can scale without blur, which is a major advantage for QR codes. PNG is fine for everyday use, but only if it has enough resolution and you do not enlarge it beyond its original size. The detailed comparison is in PNG or SVG for a QR code.
If you are sending files to a printer or designer, send SVG and ask them to:
- avoid distorting the QR code,
- preserve the quiet zone,
- avoid weak contrast,
- avoid busy backgrounds,
- test the preview at real size.
Test it the way people will use it
The best check is practical:
- Print a test version at the final size.
- Scan it from the real distance.
- Try iPhone and Android.
- Try worse lighting.
- Try the angle people will probably use.
If you have to position the phone precisely, move very close, or search for the perfect angle, the code is probably too small or has weak contrast for real use.
Frequently asked questions
Can a QR code be printed on a colored background?
Yes, but the background should be calm and clearly lighter than the code. A busy photo behind a QR code is a common problem.
Is a bigger QR code always better?
Bigger is usually safer, but it still needs good contrast and a quiet zone. Enlarging a blurry PNG is not a good solution.
Does a QR code have to be black and white?
No, but black on white is the most reliable. If you use colors, test more carefully than you would with a black-and-white code.
