Quick reference by use case
If you'd rather skip the math, here are typical scan distances and the minimum sizes they call for, based on the same 1/10th-distance rule the calculator above uses.
| Use case | Typical scan distance | Minimum size |
|---|---|---|
| Business card | 6–8 in (15–20 cm) | ~0.7 in (1.8 cm) |
| Table tent / receipt | 12–18 in (30–45 cm) | ~1–1.5 in (2.5–4 cm) |
| Flyer or poster (handheld) | 18–24 in (45–60 cm) | ~2 in (5 cm) |
| Wall poster / window decal | 3–6 ft (1–2 m) | ~4–7 in (10–18 cm) |
| Storefront window / banner | 10–15 ft (3–4.5 m) | ~12–18 in (30–45 cm) |
| Billboard | 50+ ft (15+ m) | 5+ ft (1.5+ m) |
Where the 1/10th rule comes from
It's a practical rule of thumb used across the QR code industry: a code should measure roughly one-tenth of its expected scan distance. A phone camera needs the whole code — including its quiet zone margin — clearly in frame and in focus to decode it, and codes smaller than this ratio become unreliable, especially under non-ideal lighting or with an older phone camera.
Frequently asked questions
Is this an exact requirement or a rule of thumb?
A rule of thumb. Good lighting, high contrast, and a modern phone camera can scan smaller than this; poor lighting, low contrast, or an older camera may need it larger. Treat the result as a safe minimum, not an exact cutoff.
Why does adding a logo change the recommended size?
A logo covers part of the code's error-correcting area. To keep the same scan reliability at the same distance, the overall code needs to be a bit larger so the remaining pattern still has enough resolution to decode cleanly.
What's the absolute smallest a QR code can be printed?
Most printers and phone cameras struggle below about 0.6–0.8 inches (1.5–2 cm) regardless of scan distance, since the individual modules become too fine to print and photograph cleanly. Treat that as a hard floor even for very close-up scanning.
Does the amount of data in the code matter too?
Yes. A long URL or lots of text produces a denser code (more modules packed into the same square), which needs to be printed larger than a short one to stay scannable at the same distance. Keep your encoded link as short as practical.