QR code size and scanning distance explained
A usable sizing method for cards, flyers, table signs, posters and displays, with the limits that simple rules often ignore.
A common starting point is a code width of roughly one tenth of the expected scanning distance, but this is only a test value. Dense data, weak contrast, logos, glossy material and poor lighting require a larger code. A small card code should generally not be treated as safe until a physical proof scans on several phones.
Use distance as a starting point
People often ask for one universal minimum size. That number does not exist because a QR code read from a business card and a QR code read from a shop window face different cameras, distances and lighting. A useful starting rule is to make the code about one tenth of the expected scan distance. At 30 centimetres, begin around 3 centimetres wide. At two metres, begin around 20 centimetres.
Treat that ratio as the beginning of a test, not a guarantee. A person may stand farther away than planned, the camera may use a wide lens, or the sign may be placed above eye level. Design for the least convenient realistic position.
| Use | Typical test distance | Starting width |
|---|---|---|
| Business card | 20 to 30 cm | 2.5 to 3 cm |
| Table card | 30 to 60 cm | 3 to 6 cm |
| A4 flyer or door sign | 50 to 100 cm | 5 to 10 cm |
| Poster | 1 to 3 m | 10 to 30 cm |
Data density changes the answer
A QR code containing a long address or a large block of text needs more modules than a code containing a short URL. When both are printed at the same physical size, every individual square in the dense code becomes smaller. That is why short redirect addresses are valuable for print, even when the destination itself is long.
Error correction and a centre logo also influence density. Higher error correction helps recover missing parts, but it adds information. If you add a logo, do not compensate by shrinking the entire code to fit the original layout.
- ✓Use a short HTTPS address for printed codes.
- ✓Increase size when adding a logo.
- ✓Avoid storing long text directly in a small printed code.
- ✓Do not stretch width and height independently.
Respect focus and placement
A tiny code can fail because the camera cannot resolve its modules. An enormous code can also be awkward when the user is too close to fit all four corners in the frame. Give people enough room to step back and point their phone squarely at the code.
Codes near the floor, behind a counter or high on a window may be technically large enough but physically inconvenient. Place the centre near a comfortable camera height and avoid forcing visitors to lean across furniture or traffic.
Test at final scale
Printing a proof at “fit to page” can silently change the intended dimensions. Measure the printed code with a ruler, scan it under the actual lighting and repeat the test from the expected maximum distance. For packaging, test a filled and closed product because curvature may change after assembly.
Keep a safety margin for older phones and damaged prints. A design that only scans instantly on the newest phone under office lighting is not ready for a large print run.
Practical next step
Calculate a starting size from the real viewing distance, print one proof at 100 percent scale and scan it with two phones before ordering the full run.
Create a test QR code ↗