Why QR code size matters
A QR code only scans if its modules are large enough for the camera to resolve at the distance it will be scanned from. Make it too small and the camera sees a blur; make the data too dense and the individual modules merge together. Size and data density are the two biggest reasons otherwise-perfect codes fail in the real world.
The good news: there are simple rules of thumb that get you a scannable code on the first try, every time — the 1/10 scan-distance rule for physical size, and short links for density.
The 1/10 scan-distance rule
A reliable rule of thumb is that the printed side length of a QR code should be about 1/10th the distance at which it will be scanned. A code scanned from 1 m (3 ft) should be at least 10 cm (4 in) wide; a code scanned from 30 cm (1 ft) should be at least 3 cm (1.2 in) wide.
This is a minimum, not a target — bigger is always more reliable. When in doubt, go one size up, especially in low light or where the code may get dirty.
Recommended minimum size by use case
Here are practical minimum sizes for common placements. Treat these as floors, not ideals — test the printed code with a real phone in the real lighting before you commit to a print run.
| Use case | Recommended min size | Typical scan distance | Notes |
|---|---|---|---|
| Business card | 2 × 2 cm (0.8 in) | 10 cm (4 in) | Smallest practical size; use a short URL and level M, no logo or a tiny one. |
| Flyer / handout | 3 × 3 cm (1.2 in) | 30 cm (1 ft) | Level M; keep the destination URL short so the grid stays simple. |
| Table tent (menu) | 5 × 5 cm (2 in) | 50 cm (1.5 ft) | Level H if you add a logo; print matte to avoid glare under restaurant lighting. |
| Poster | 10 × 10 cm (4 in) | 1 m (3 ft) | Follows the 1/10 rule; export SVG or a 1024px+ PNG so it stays sharp. |
| Billboard / sign | 25 × 25 cm (10 in) | 2.5 m (8 ft) | Use vector SVG; keep a generous quiet zone and high contrast. |
| Screen / digital | 240 × 240 px | Arm’s length | Render at 2× for retina; never go below 240px or it won’t scan. |
| Packaging | 1.5 × 1.5 cm (0.6 in) | 5–10 cm (2–4 in) | Only with a very short URL and level H; test extensively before mass production. |
Module size and data density
A QR code is a grid of modules — 21×21 for a tiny amount of data up to 177×177 for the maximum. For a fixed physical size, more data means more modules, which means each module is smaller and harder for a camera to resolve.
This is why short links matter: a 20-character URL produces a far simpler grid than a 200-character one. Always shorten your destination URL before generating the code, especially for small prints like business cards or packaging.
Error correction and size
Higher error-correction levels (Q, H) add redundant data, which means more modules and a denser grid for the same payload. Pair a high level with a short link so the code stays easy to scan.
Use level M by default. Use H whenever you embed a centered logo, print on rough surfaces, or expect wear — and combine H with the shortest possible URL so density stays manageable.
Print vs screen
For print, export vector SVG (scales to any size with no quality loss) or a high-resolution PNG of at least 1024 px. Never scale a small raster image up — it blurs and stops scanning.
For screens, render the code at 240×240 px minimum and ideally 2× that for retina displays. Keep the quiet zone at least 4 modules wide on every side so the scanner can find the code.
Frequently asked questions
How big should a QR code be?
About 1/10th the scan distance: 10 cm (4 in) for a 1 m (3 ft) scan, 3 cm (1.2 in) for a 30 cm (1 ft) scan. Never go below 2×2 cm (0.8 in) unless you have a very short URL and have tested thoroughly.
What is the minimum QR code size for scanning?
Roughly 1.5×1.5 cm (0.6 in) with a very short URL and error-correction level H, but 2×2 cm is a safer floor. Smaller codes can scan only with short payloads, strong contrast, and good lighting.
Does more data make a QR code bigger?
At a fixed physical size, more data means more modules and smaller individual modules, which are harder to scan. Keep destination URLs short so the grid stays simple and the code scans reliably at small sizes.
How big should a QR code be on a business card?
At least 2×2 cm (0.8 in), with a short link and level M. Add a logo only at level H, and keep the logo small so it doesn’t cover the finder eyes in the corners.