HandyQRCodeThe 10:1 rule
A QR code should be about one tenth as wide as the distance it is scanned from. Scanned from 1 metre → 10 cm wide. From 30 cm (a table) → 3 cm.
Typical sizes
| Where | Scanning distance | Code width |
|---|---|---|
| Business card, product label | 15–25 cm | 2–2.5 cm |
| Flyer, table tent, menu | 20–40 cm | 3–4 cm |
| A4 poster on a wall | 0.5–1 m | 6–10 cm |
| Shop window, A2 poster | 1–2 m | 10–20 cm |
| Banner, trade show wall | 3–5 m | 30–50 cm |
More content needs a bigger code
Every character adds small squares (modules). A short link makes a coarse, easy code; a full contact card or a long link with tracking tags makes a fine, dense one. Dense codes need more size to scan reliably. Each module should be at least about 0.4 mm when printed, and 0.5 mm or more is safer.
- Use short links: a page on your own domain (
yourshop.com/menu) instead of a long shared-document link. - Leave out optional fields in contact cards for small business cards.
- Error correction “Medium” is a good default. “High” makes the code denser, so only use it with a logo or for codes that may get damaged.
Other things that affect scanning
- Contrast: a dark code on a light background. Light-on-dark and pastel colours fail on many phones.
- Quiet zone: keep the white margin around the code; don’t let text or graphics touch it.
- Surface: glossy, curved or reflective surfaces need a slightly bigger code.
- Print quality: use SVG or PNG at 4×, never a screenshot.
Barcode sizes
- EAN-13 / UPC-A: nominal size about 37 × 26 mm. They can usually be printed between 80% and 200% of that. Don’t shorten the bars.
- Code 128 / Code 39: no fixed size; use a bar width of at least 2 in the generator for printing and keep about 6 mm of white space on both sides.
Always print one test and scan it from the real distance before printing in quantity. Printing labels? See how to print on Avery label sheets.