How big should a printed QR code be?

Start with distance, then test the print

A width around one tenth of the intended scanning distance is a useful starting point for a layout, not a universal minimum or a scanning guarantee. At 300mm, that gives 30mm to try. The camera, lighting, print material, contrast and number of modules in the symbol all affect the result.

The table below gives planning estimates for short links with dark-on-light artwork. It is not a set of measurements from a device test. Before approving a print run, make a full-size proof on the intended material and test it at the expected distance with several phones, including an older device.

Sizes by scanning distance

Notes on the rows people get wrong:

• Business card. A card is scanned deliberately and close. A smaller code may work, but there is no universal 15mm floor. Test the actual encoded content and stock; the constraint is tight enough that cards have their own page.
• Shop window. Glass adds reflections the table cannot see. Test from the pavement, in daylight and after dark, not from inside the shop.
• Vehicle livery. The arithmetic assumes the vehicle is parked. Nobody scans a moving van, so size for where it parks, not for the traffic behind it.
• Roadside banner. A code read from a passing car is decoration. Size it for the person who walks up to the banner, and put the address in plain text beside it for everyone else.

Where a location falls between rows, take the bigger number. Nobody has ever reprinted a poster because the code scanned too easily.

A longer address needs a bigger print

The pattern is a grid of modules. Its dimensions depend on the encoded data, encoding mode and error-correction level. A longer address can require a larger grid, but a short link does not always produce the same module count. At a fixed printed width, more modules mean smaller individual modules.

For a standard QR symbol with a four-module quiet zone on each side, total width is (symbol modules + 8) × module width. For example, a 33-module symbol with 0.5mm modules occupies 20.5mm including its border. A 57-module symbol at the same module width occupies 32.5mm. These are arithmetic examples, not guaranteed minimum scanning sizes.

DENSO WAVE explains how to choose module size for the printer and reader and calculate the complete code area including the quiet zone. Check the module count of the actual code you will print.

A short redirect address can reduce the data in the pattern, but it adds a dependency on the redirect service. With QR That Lasts, cancelling a paid subscription moves an open account to Free; closing or suspending the account, archiving a code or blocking an unsafe destination stops its redirects. Review the service terms before committing to a print run.

The border is inside these numbers

Every width in the table includes the quiet zone, the empty margin a scanner uses to find the pattern. For a standard QR symbol, leave at least four modules clear on every side. Its physical width therefore depends on the module size; it is not a fixed 3mm margin. The print guide explains why it is load-bearing and what happens when a photograph runs underneath it.

When the space is smaller than the table says

Three things work. Shorten what the pattern carries, which usually means a redirect link instead of a full address. Move the code somewhere the reader can get closer to it. Or print one at the size you have, on the real stock, and test it at the real distance with a phone that is not yours.

Do not approve a smaller layout solely because its on-screen preview scans. A difficult print can take longer to recognise or fail altogether. Record the phones, distance, lighting and material used in the proof test so the printer and client know what was actually checked.

Once the size is settled, the file you send the printer decides whether the edges survive: SVG, EPS, PDF or PNG is its own question.