The 10:1 rule
A common rule of thumb: the QR code should be about one-tenth of the scanning distance wide.
| Scanning distance | Minimum width | Typical use |
|---|---|---|
| 30 cm (1 ft) | 3 cm (1.2 in) | Business cards, packaging, table tents |
| 1 m (3.3 ft) | 10 cm (4 in) | Flyers, counter signs, menus on a wall |
| 2 m (6.6 ft) | 20 cm (8 in) | Posters, shop windows |
| 5 m (16 ft) | 50 cm (20 in) | Banners, event signage |
For anything handheld, about 2 cm (0.8 in) is a practical floor. Go bigger when the code holds a lot of data — a long URL or a full vCard makes the pattern denser.
Quiet zone
The QR spec asks for an empty margin of 4 modules (the small squares) on every side. Don’t let text, borders, or images touch the code.
Contrast and colors
- Dark foreground on a light background scans best.
- Inverted codes (light on dark) fail on some scanner apps — avoid them for print.
- Brand colors are fine if contrast stays high. Avoid pastel-on-white and red-on-black.
Error correction
| Level | Can recover about | When to use |
|---|---|---|
| L | 7% damage | Clean digital screens |
| M | 15% | Everyday print (QR Studio default) |
| Q | 25% | Rough surfaces, outdoor use |
| H | 30% | Codes with a center logo (QR Studio uses this when you add one) |
Resolution for print
A 1024 px PNG from QR Studio prints sharply up to about 3.4 in (8.7 cm) at 300 DPI. Because QR codes are made of square blocks, you can scale them larger in design tools using “nearest neighbor” resizing without blurring edges.
FAQ
What is the smallest a QR code can be?
Around 2 cm × 2 cm (0.8 in) for close scanning, and only if the content is short and the print is crisp.
Why won’t my QR code scan?
The usual culprits: too small for the distance, low contrast, no quiet zone, a logo that’s too big, or a glossy surface causing glare.
Does a longer URL make the QR code bigger?
It makes the pattern denser (more modules), so you need a larger print size to keep each square readable. Use short URLs when you can.
Can I put a QR code on a business card?
Yes — 2–2.5 cm is typical. A vCard QR code lets people save your contact in one tap.
Related
Make a print-ready PNG.
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