Minimum size for a QR code
Last updated 16 September 2026
The question is never "how big should a QR code be". It is "how far away will someone stand when they scan it". Size only means something relative to distance.
The working rule
The scan distance should be roughly ten times the width of the code. A 2cm code works at about 20cm. A 10cm code works at about a metre. A 1m code works from ten metres.
This is not exact. Camera quality, lighting and code density all shift it. But it gets you into the right order of magnitude, which is where most people go wrong. A code intended for a poster that is sized for a business card is the classic error.
Common sizes
- Business card, 2cm. Scanned at arm's length. Fine for a short URL. Too small for a full vCard.
- Leaflet or menu, 3 to 4cm. Comfortable handheld scanning. The most forgiving everyday size.
- Poster at eye level, 8 to 10cm. Scanned from about a metre.
- Window or floor sign, 20cm or more. People scan these while walking past, so it has to work at a distance and quickly.
- Billboard, 1m or more. The code has to be legible from a car, and the payload should be short to keep the grid coarse.
Density changes everything
Two codes at the same physical size are not equally scannable. A short URL produces a coarse grid with big modules. A long URL or a vCard produces a dense grid with tiny ones. At 2cm, the coarse code scans easily and the dense one may not scan at all.
So the size rule is really about module size, not code size. Each module needs to be resolvable. Roughly, you want modules no smaller than a millimetre for close scanning, and larger if the code is being viewed at an angle or in poor light.
This gives you two levers. Make the code bigger, or make the payload smaller. Shrinking the payload is usually easier and always free. A shortener plus a short code beats a giant print every time.
The quiet zone
Every QR code needs a margin of empty space around it, called the quiet zone. The standard is four modules wide. Without it, the scanner cannot tell where the code ends and the background begins, and the scan fails.
The generator here includes a margin. If you take the image into a design tool, do not crop it off. Putting a code flush against a border, or dropping it onto a busy pattern, removes the quiet zone and breaks it. Give it clear space on all four sides.
Print quality
Size only helps if the print is clean. Inkjet output on absorbent paper bleeds slightly, which blurs module edges. Laser printing on plain paper is sharper. For anything smaller than about 3cm, print quality matters as much as the size itself.
Do not print at the smallest size your printer can manage and hope. Print a proof, scan it, then commit to the full run.
A quick method
- Decide the realistic scan distance.
- Multiply by roughly ten to get the minimum width in centimetres.
- If that size is impractical, shorten the payload instead.
- Print one proof at the intended size.
- Scan it, at the real distance, in the real light.
Step five is the one people skip, and it is the only step that actually proves anything.