# What size should a QR code be?

> Printed width should be at least the scanning distance divided by ten. A code read from 30 cm needs 3 cm; from 2 m, 20 cm; from 10 m, 1 m. If there is not enough room, shorten the payload so the code has fewer, larger modules rather than shrinking the code.

Source: https://useqr.app/docs/print/qr-code-size-for-print · Last reviewed 2026-08-21 · UseQR is free forever, MIT licensed, no signup.

---

## The ten-to-one rule

```
minimum printed width = scanning distance ÷ 10
```

| Where it is | Distance | Minimum code width |
|---|---|---|
| Business card, in the hand | 25 cm | 2.5 cm |
| Restaurant table tent | 35 cm | 3.5 cm |
| Product label on a shelf | 50 cm | 5 cm |
| Poster in a corridor | 1 m | 10 cm |
| Wall poster, eye level | 2 m | 20 cm |
| Sign across a lobby | 3 m | 30 cm |
| Large format signage | 10 m | 1 m |

That is the **code**, excluding the frame, caption and quiet zone.

## Why the rule works

It is a proxy for angular size. A phone camera needs roughly 2–3 pixels per module to
threshold reliably. Dividing distance by ten produces a code whose modules subtend enough
angle for a typical phone camera, with margin for imperfect focus and lighting.

It assumes a **moderate payload**. A very dense code needs more than the rule suggests,
which is why payload length and size must be decided together.

## The module floor

The rule's real constraint is module size:

| Condition | Minimum module |
|---|---|
| Offset print on coated stock | 0.4 mm |
| Uncoated stock (ink spread) | 0.5 mm |
| Thermal transfer at 203 dpi | 0.5 mm |
| Thermal transfer at 300 dpi | 0.34 mm |
| Laser-marked metal | 0.5 mm |
| Screen print on fabric | 1.0 mm |
| Laser-engraved wood | 1.0 mm |
| 3D print | 1.5 mm |
| Embroidery | 2.0 mm |

Divide your available width by the module count to check.

## Worked example

A URL of 45 characters at error correction M is version 3 — 29 modules, plus 4 modules of
quiet zone on each side = 37 module widths total.

On a table tent at 35 cm, the rule wants a 3.5 cm code. 35 mm ÷ 29 = **1.2 mm per module** —
comfortably above every floor above. Good.

Add 100 characters of UTM parameters and it becomes version 6 (41 modules): 35 mm ÷ 41 =
**0.85 mm**. Still fine, but you have spent margin for nothing.

Put the same code on a shelf-edge label at 15 mm: 15 ÷ 41 = **0.37 mm**, below the thermal
floor. Now you must shorten the payload.

## Do the arithmetic, do not eyeball it

Our [size calculator](/size-calculator) takes the payload, the distance and the medium and
returns the number. It is faster than arguing about it in a design review.

## FAQ

### What is the minimum size for a QR code?
There is no universal minimum — it depends on the module count. As a rule, printed width must be at least the scanning distance divided by ten, and each module must be at least 0.4 mm for offset printing.

### How big should a QR code be on a poster?
Ten to thirty centimetres, depending on whether it is read from one metre or three. Most posters carry codes far smaller than this, which is why they go unscanned.

### Can I make a QR code smaller than the rule suggests?
Only by shortening what it encodes. Fewer characters means a lower version, fewer modules, and larger modules at the same overall width.

### Does the quiet zone count toward the size?
No. The ten-to-one rule applies to the code itself; the four-module quiet zone is additional clear space around it.

## Try it

- https://useqr.app/size-calculator
- https://useqr.app/validate
- https://useqr.app/url