What size to print a QR Code

Printing a thousand flyers and finding out the QR Code will not scan is an expensive, avoidable mistake. It nearly always has the same origin: the code was sized by what looked good in the layout rather than by how far away people would be scanning from.

The 10-to-1 rule

The practical reference used in the industry is simple: the side of the QR Code should measure at least a tenth of the scanning distance. If someone will scan from 2 metres, the code needs at least 20 cm.

That is a minimum, not a target. Working with double gives headroom for bad light, an old camera and an unsteady hand — the three factors that break scanning in the real world.

Table by situation

• Business card — scanned from 20-30 cm, minimum 2 to 3 cm.
• Table menu — scanned from 30-40 cm, minimum 3 to 4 cm.
• Product packaging — scanned from 30 cm, minimum 3 cm.
• Flyer and leaflet — scanned from 30-50 cm, minimum 3 to 5 cm.
• Wall poster — scanned from 1-1.5 m, minimum 10 to 15 cm.
• Shop window — scanned from 1.5-2 m, minimum 15 to 20 cm.
• Event banner — scanned from 3-5 m, minimum 30 to 50 cm.
• Vehicle side — scanned from 3-5 m, minimum 30 to 50 cm.
• Building facade and billboard — scanned from 15-20 m, minimum 1.5 to 2 m.

The white margin counts towards the size

The specification requires a clear zone equivalent to 4 modules around the whole code. It is not decoration: without it, the reader struggles to identify where the code ends.

When reserving space in the layout, account for code plus margin together. Letting a headline, border or photo touch the QR Code is one of the most common failures and one of the easiest to avoid.

Density changes everything

The numbers above hold for codes of moderate density. A code with a lot of content has smaller modules in the same space, and therefore needs more physical size.

• A phone QR Code has few modules and is the most forgiving of all.
• A link QR Code with a short URL is comfortable.
• A full contact QR Code or long text code may need 50% more size for the same distance.

If in doubt, shorten the content rather than enlarging the paper. Understand why in the article on how a QR Code works.

File resolution

• For print, use SVG. It is vector: it scales to any size without losing sharpness, and it is what print shops prefer to receive.
• If you need PNG, export at least 300 DPI at final size. A 3 cm code needs roughly 350 pixels per side; a 10 cm one about 1,180.
• Never enlarge a small PNG. Edges get jagged, modules lose definition and the scan rate collapses.

Precautions by material

• Matte paper is the best case. No reflection, high contrast.
• Glossy paper and varnish reflect ambient light and can wash out part of the code under a direct lamp. Increase the size and prefer a matte finish over the code area.
• Curved surfaces — bottles, cans, mugs — distort scanning. Keep the code on the flattest area possible and increase the size.
• Fabric absorbs ink and blurs module edges. Use sparse codes and generous sizing.
• Glass and clear stickers need a solid background behind them. A code over a varying background barely scans.
• LED screens and video walls — watch for excessive brightness and refresh rate, which can confuse the camera.

The test that settles it

Before approving final artwork, print a proof at real size, on the same printer and the same paper. Scan it with two different phones, from the real distance and in the real lighting of the location.

If it reads first time without stepping closer, it is fine. If you have to move nearer or insist, increase the size. Five minutes of testing costs less than a whole print run.