QR Generator.au

Guide

How big should a QR code actually be?

One rule covers almost every case, and one reference table covers the rest. Both are below, along with the three mistakes that kill more printed codes than sizing ever does.

The rule and the table

The 10:1 rule

Minimum width = scanning distance ÷ 10.

Someone scanning from one metre needs a code at least ten centimetres wide. It is a floor, not a target — treat it as the smallest defensible size and go larger whenever you have the room.

Print size reference

PlacementDistanceMinimumComfortable
Business card20 cm2 cm2.5 cm
Table card / menu30 cm3 cm4 cm
Product label25 cm2.5 cm3 cm
Counter sign60 cm6 cm8 cm
A4 flyer / poster1 m10 cm12 cm
Window decal1.5 m15 cm20 cm
A-frame on the footpath3 m30 cm40 cm
Real estate signboard5 m50 cm65 cm
Vehicle / ute signage5 m50 cm60 cm
Building sign10 m1 m1.3 m
Billboard20 m2 m2.6 m

Use the comfortable column for anything people scan while moving, in low light, or on a wet day.

Data length changes the answer

The rule assumes a reasonably short payload. More characters means more modules packed into the same square, so each module gets physically smaller and harder to resolve.

Encoded dataTypical gridSize multiplier
Short link (~25 chars)21–29 modules×1.0
Normal URL (~60 chars)33–37 modules×1.2
URL with tracking (~150 chars)45–57 modules×1.5
Full vCard (~250 chars)57–73 modules×1.8

The cheapest fix for a code that is too dense is not a bigger print — it is a shorter link.

Three mistakes that matter more than size

  1. Cropping the quiet zone. The blank border must be at least four modules wide. Designers trim it constantly, and it is the most common cause of a professionally printed code that never worked.
  2. Using a raster file for print. A PNG stretched to A-frame size gives soft, uneven module edges. Export SVG and the problem disappears.
  3. Weak contrast. Pale grey modules on white, or a code over a photo, fails on many phones even at generous sizes. Dark on light, always.

Error correction by surface

SurfaceLevelReason
Screen, clean paperMNothing will damage it
Business card, packagingQHandling and abrasion
Table sticker, laminated menuHSpills, wiping, cutlery
Outdoor signage, vehicleHWeather, dirt, partial obstruction
Any code with a logoHThe logo blanks the modules it covers

Once you have picked a size, generate the code and download the SVG — then print one and scan it before committing to the run.

Straight answers

Sizing questions

What size should a QR code be?

Divide the scanning distance by ten. A code read from 30 cm needs to be about 3 cm wide; from 3 m, about 30 cm. Add margin on top for dense codes, poor lighting or older phone cameras.

What is the smallest a QR code can be?

Around 2 cm square in print, and only with short data, a clean quiet zone and strong contrast. Below that, ordinary print tolerances start to blur individual modules.

What resolution do I need for printing?

Use vector SVG or PDF and resolution stops mattering — the code scales perfectly. If you must use a raster file, target 300 dpi at the final printed size.

How big should a QR code be on a business card?

About 2 cm square. Keep the encoded data short, keep the four-module quiet zone, and print one test card before ordering a box.

Does the amount of data change the size I need?

Yes. More data means more modules in the same area, so each module is physically smaller. A long tracking URL can need a code 50% larger than a short link to scan from the same distance.