How big should a QR code be? The 10:1 rule, by placement
Too small and it won't scan. Here's how to turn scan distance into an exact size.
Print a QR code at least one-tenth as wide as the farthest distance it will be scanned from: a code read from 25 cm away needs about 2.5 cm, and a poster read from 3 metres needs about 30 cm. Below roughly 2 x 2 cm most phone cameras struggle whatever the distance. For a number from your own distance, use the QR code size calculator.
That is the 10:1 rule: about 1 unit of width for every 10 units of scanning distance. A code people scan from 10 inches away should be about 1 inch square, and one scanned from 10 feet across a parking lot should be about a foot wide. Round up rather than down, because a code that runs a little large always scans and one that runs a little small sometimes doesn't.
Minimum QR code size by placement
- Business card or product label: about 0.8 to 1 inch (2 to 2.5 cm), scanned at arm's length.
- Flyer or menu: around 1.2 inches (3 cm) for a handheld read.
- Poster or window sign: 2 to 4 inches, since people scan from a few feet back.
- Yard sign or banner: 8 inches and up, sized for the curb.
Treat those as starting points, and size for the farthest realistic reader, not the nearest. The table at the end of this page gives the minimum for each scan distance from a business card to a billboard. Its first row is the arithmetic: 1 cm at 10 cm. In practice about 2 cm is the smallest size worth printing, and bigger is always safer, especially outdoors or where people scan in motion.
Longer links need a bigger code
The rule assumes a sparse code. A long URL, or a high error correction level, packs more modules into the same square, so each one prints smaller and the code needs more room to stay readable. A short link keeps the code sparse, which is one reason a code that points at a short redirect scans more easily than one with a long address baked in.
Leave room for the quiet zone
The size that matters is the code plus its margin. A QR code needs an empty border around it, the quiet zone, of about four modules on every side, or a scanner struggles to find where the code begins. Budget for that margin instead of cropping the code tight to fit a layout.
Print it sharp, not just big
A large code that prints blurry fails as surely as a small one. Print from a vector file (SVG) where you can, and if you're printing a PNG, render it at around 300 DPI at final size so the edges stay crisp. Higher error correction buys more margin for damage: it keeps a code readable even when part of it is smudged, wrapped around a curved bottle, or covered by a logo.
Every TangoQR code downloads as an SVG and a PNG, so you can scale it from a business card to a billboard out of the same file.
Scan distance to minimum QR code size
| Scan distance | Minimum QR size | Typical use |
|---|---|---|
| 10 cm (4 in) | 1 cm (0.4 in) | Business card, product label |
| 30 cm (1 ft) | 3 cm (1.2 in) | Menu, table tent, flyer in hand |
| 1 m (3 ft) | 10 cm (4 in) | Poster, shelf talker |
| 2 m (7 ft) | 20 cm (8 in) | Yard sign, window display |
| 5 m (16 ft) | 50 cm (20 in) | Wall banner, trade-show booth |
| 10 m (33 ft) | 1 m (3.3 ft) | Billboard, building signage |
Source: The 10:1 rule applied to each distance
Common questions
- How big should a QR code be?
-
At least one-tenth as wide as the farthest distance it will be scanned from. A code read from 25 cm away needs about 2.5 cm, and a poster read from 3 metres needs about 30 cm.
- What is the minimum size for a QR code?
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About 2 x 2 cm (0.8 inch) for a code scanned at arm's length. Below that most phone cameras struggle whatever the distance. A code with a long link or a logo needs more room than that.