Business card QR code size Count the squares, then measure.

Every “minimum QR size” you have read is a module count and a module size multiplied together, with one of them hidden. The module count comes from the version: version 1 is 21 modules across, and each version up adds four. Which version you get is decided by how many characters you encode and how much error correction you ask for.

So the first question is not how big. It is what the code holds. Here is one made-up person encoded four ways by the same encoder our free generator uses.

A link stays small because it is short: the details live on the page it opens, not in the code. A vCard carries the contact itself, so every field you add grows the grid. The trade between the two is covered in our vCard QR guide and on QR code business cards. This page is about the size, once you have chosen.

GS1 is the standards body behind retail barcodes. Its specification sets the size of the module, which it calls the X-dimension, for QR codes on products: a minimum of 0.396mm, a target of 0.495mm and a maximum of 0.990mm, with a quiet zone four modules wide on every side. GS1 UK says these codes are meant to be read at the till and by phones, which is why we use them here.

Two honest caveats. First, GS1 wrote this for printed packaging, not for business cards, and nobody publishes a figure for “a phone at arm’s length in a dim room”. Second, the minimum is a floor, not a recommendation. Where you have the room, use the target.

You will also see much smaller numbers. Denso Wave, who invented the QR code, works an example at 0.254mm a module: that is what a 400dpi printer produces with four dots per module. It is a printer’s limit, not a phone’s, and it is not a size we would print a business card at.

Read across the lean vCard row. At the minimum module it needs 22.6mm of printed code. Print it 20mm wide instead, say, and each of its 57 modules is 0.35mm, below GS1’s floor. The same 20mm gives the link’s 29 modules 0.69mm each, comfortably above the target. That is the whole argument for putting a link on a small card and saving the vCard for a larger surface.

Both Denso Wave and GS1 require a margin four modules wide on all sides, with nothing printed in it: no border, no text, no edge of the card. That adds eight modules to the width, which is why the table has two columns for each module size. On a 57-module vCard, the margin alone is 4.0mm at the target size.

Whatever generator you use, look at how much white border the download already has before you place it, and make up the difference to four modules in the layout. Designers trimming that white to line the code up with other elements is one of the easiest ways to break one.

Denso Wave lists four levels: L restores about 7% of a damaged code, M about 15%, Q about 25% and H about 30%, and notes M is the one most often chosen. Our generator uses M. Here is what the choice does to the same contact:

• L: 49 modules, so 28.2mm with its margin at the target size.
• M: 57 modules, 32.2mm.
• Q: 65 modules, 36.1mm.
• H: 73 modules, 40.1mm.

A business card lives in a pocket, not a factory, so there is little reason to pay for H. On this contact, each level up costs 8 more modules across, on the same card.

If you would rather the code on your card never needed reprinting, point it at a page instead. A Cardr card is a signed Apple Wallet pass whose QR opens your page at a short address, free, and you can change the details behind it after the card is printed.