What Size Should a QR Code Be for Printing?
· 2 min read · Scanlexa team
A QR code that scans perfectly on your laptop screen can fail completely on a poster across the room. Size is the most common reason printed codes don't work, and it's the easiest thing to get right.
The 10-to-1 rule
Make the code at least one tenth as wide as the distance it will be scanned from. Someone standing 2 metres from a poster needs a code at least 20 cm wide. Someone holding a flyer at arm's length (about 40 cm) needs at least 4 cm.
This rule works because phone cameras need each square of the pattern to cover enough pixels to tell dark from light. Further away, every square looks smaller, so the whole code has to grow.
| Where it's printed | Usually scanned from | Minimum width |
|---|---|---|
| Business card | 25 cm | 2.5 cm |
| Flyer or menu | 40 cm | 4 cm |
| Table tent | 60 cm | 6 cm |
| A3 poster | 1.5 m | 15 cm |
| Banner or shop window | 3 m | 30 cm |
| Billboard | 10 m | 1 m |
Our QR code size calculator does this for any distance.
Never smaller than 2 cm
Even for things held in your hand, like business cards and product labels, don't go below 2 cm × 2 cm. Smaller than that, many phone cameras can't focus close enough to read it, especially older or budget phones.
Long content needs a bigger code
Every QR code is a grid of squares (modules). A short link might make a 25 × 25 grid; a full contact card with an address can make a grid of 70 × 70 or more. Packed into the same width, those squares are much smaller and harder to read.
A good minimum is 0.4 mm per square, plus a margin of four squares on every side. So a dense 77 × 77 code needs at least 3.4 cm, even up close.
The easiest way to keep a code simple is a dynamic QR code: the pattern holds only a short link, however long the real destination is. See static vs dynamic QR codes for how they work.
Leave a quiet zone
The blank margin around a code (the "quiet zone") is part of the code. Scanners use it to find where the code starts. Keep it at least four squares wide, and don't let text, borders or photos touch the pattern.
Surfaces that need extra size
Go a size up when the code will be:
- On a glossy or laminated surface, where reflections hide parts of the pattern
- On a curved surface like a bottle or cup
- Behind glass, such as a shop window
- In poor light, like a restaurant at night
Test before you print hundreds
Print one copy at the real size, put it where it will be used, and scan it from where people will actually stand, with two or three different phones. It takes five minutes and can save a whole print run.
When you design a code with Scanlexa, the designer scans it in your browser after every change and warns you about low contrast or a logo that's too big, before you download.