QR code size chart: minimum print sizes by scan distance

Most QR print failures start with a code sized for the layout instead of the reader. One division prevents them: take the farthest distance a person will scan from and divide by 10. The answer is your minimum code width.

How do you work out QR code size from scan distance?

Measure the farthest point a scanner will stand at, then divide by 10. A table card scanned from 40 cm needs a code 4 cm wide. A window sign read from 1.5 meters needs 15 cm. The ratio comes from camera optics: at range, the phone captures fewer pixels per module, and below the 10:1 line most cameras stop resolving the pattern. Our sizing and printing guide walks through the numbers behind the rule.

The rule assumes decent lighting and a code of ordinary density. Dim corridors, glossy laminate and glass between scanner and code all eat margin, so treat the result as a floor rather than a target.

What size should a QR code be on common formats?

Apply the rule to the places codes get printed and you get a chart worth keeping:

• Business card, scanned in hand: 2 cm minimum. Smaller than that and older cameras struggle to resolve the modules. More on business cards.
• Flyer or leaflet, scanned at arm's length: 2 to 3 cm.
• A3 poster, read from a meter or two: 4 to 6 cm. See our notes on posters.
• Storefront window, scanned from the pavement: 10 to 15 cm. See storefront windows.
• Billboard, scanned from across a road: 1 meter and up.

Each figure is a minimum. Paper stock, ink spread and viewing angle vary, and none of them vary in your favor. Print bigger whenever the layout allows.

Does the quiet zone count toward the size?

No, and that catches designers out. The quiet zone is the empty margin around the pattern, 4 modules wide on all four sides, and scanners use it to find the code's edges. Budget for it on top of the widths above: a 4 cm code needs roughly 5 cm of clear space once the margin is in. Cropping the margin to fit a tight layout breaks scanning faster than shrinking the code itself.

Does URL length change the minimum size?

Yes. More characters mean more modules, and more modules at the same print size mean smaller modules. A destination URL with 200 characters of tracking parameters produces a far denser pattern than a short link, and the dense version needs a bigger print to stay readable.

A dynamic QR code sidesteps the problem. The pattern encodes a short link, and the long destination lives behind it on the server. You can tag the destination with as many parameters as your analytics wants; the printed code stays sparse either way.

What should you check before sending to print?

A proof costs one sheet of paper. Run this list on it:

• Print at final size on the final material, then scan with an iPhone and an Android.
• Stand at the real scan distance, in the real lighting.
• Confirm dark modules on a light background, with the quiet zone clear of artwork.
• Open the destination and watch it load on mobile data rather than office Wi-Fi.
• For a dynamic code, confirm the destination is the live version. You can edit it after the run, and checking now spares you the correction.

Once the proof scans from the real distance on both platforms, the run itself holds no surprises.