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How big does a QR code on a business card need to be to scan reliably?

There is no single official number for every card. What decides how easily it scans is the size of one module once printed, and that grows as the content shrinks. So the quickest route to a small code that scans well is shorter content, a full blank margin, an SVG file, and a proof at the real size.

Published · 2 min read

Why content matters more than size

A code is a grid of square modules, and the number of modules per side goes up with the amount of content. Print two codes at the same width and the denser one has smaller modules, so the camera has to get closer or be sharper to read it. On a business card with little room, that is the difference between an instant scan and repeated attempts.

An example with figures from the tool

A contact card for Sara Alotaibi of Al Waha, with the mobile number +966 50 123 4567, the email sara@example.com and the website https://example.com:

  • As vCard 3.0: 178 bytes of content, and the symbol comes out 53 modules wide.
  • As MeCard: 103 bytes, and the symbol comes out 41 modules wide.
  • Just a short link such as https://example.com: 19 bytes, and the symbol is 25 modules wide.

Add four modules of margin on each side, then imagine printing each at 2 cm wide including the margin. The arithmetic gives a module of about 0.33 mm for the vCard, about 0.41 mm for the MeCard, and about 0.61 mm for the short link. The short link gives you nearly twice the module size of the full card.

Practical steps for the card

  1. Decide what the code is for: saving the contact directly, or opening a page with all your details.
  2. For a contact, choose 'Contact' in the QR code generator, pick MeCard if space is tight, and leave out fields you do not need, such as address and note.
  3. Keep the quiet-zone margin at 4 modules; do not trim it to save space.
  4. Download SVG and send it to the printer, since it stays sharp at any size.
  5. Ask for a printed proof at the final size and scan it with more than one phone before ordering the full run.

Common questions

Is there a rule for scanning distance versus size?

There are rough rules of thumb in circulation, but they are not part of the specification and vary by camera. Rely on a real test at the real size.

Should the code go on the back of the card?

That is a design choice, but the back usually gives you more room and a cleaner blank margin around the code.