How big should a QR code be?

QR codes fail for one reason more than any other: they are printed too small for the distance people scan them from. A simple rule of thumb prevents almost all of it — minimum size ≈ maximum scan distance ÷ 10. If people will scan from one metre away (100 cm), the code should be at least 10 cm across. From a business card held at 20 cm, about 2 cm is plenty. Work out the farthest realistic scan distance, divide by ten, and that is your minimum width. When in doubt, round up.

Every QR code needs a margin of empty space around it, called the quiet zone. Scanners rely on that clear border to tell where the code starts and ends. A good rule is a margin at least four modules wide — roughly the width of four of the small squares in the pattern — on all sides. Do not crowd the code with text, logos, or a busy background right up to its edge, and never let it bleed off the edge of the print.

The right size shifts with where the code lives and how far away people stand. A code on a product label is scanned from a few centimetres; one in a shop window from across the pavement; one on a billboard from the far side of a road. The table below applies the divide-by-ten rule to the most common placements so you can start from a sensible minimum.

Never send a large print run without testing first. Print the code at the exact final size, then scan it from the closest and farthest distances people realistically will — with a few different phones, in the actual lighting. If any phone hesitates, make the code bigger or increase the contrast. Five minutes of testing is far cheaper than reprinting a thousand posters.

Even a perfectly sized code is worth pairing with a dynamic code. Because a dynamic code lets you change the destination without reprinting, you can fix a wrong link or update a campaign long after the code is on the wall — so a careful sizing test becomes the only thing standing between you and a code that keeps working for years.

Minimum printed sizes for common placements, based on the size ≈ distance ÷ 10 rule. Round up when in doubt — a slightly larger code never hurts.

Note: Rule of thumb: minimum size ≈ maximum scan distance ÷ 10. These are minimums for a clean, high-contrast code with a clear margin — round up if the code is complex, printed on a rough surface, or scanned in poor light. Always test with a few phones before a large print run.

Rules of thumb are a starting point. Phones, printers, finishes, curves, lighting and viewing distance change the result. Test the final artwork on the final material and keep a record of the approved version.