Guide · with calculator
How small can a printed QR code be?
There's an exact answer, and it's a one-line formula: (modules + 8) × 0.6 mm. Here's what that means, a calculator for your own content, and the extra rules that apply when the code goes on fabric rather than paper.
Work it out for your content
Paste what your code should hold - a link, WiFi login, anything - and see the module count, the minimum reliable print size, and how far away it will scan.
25 × 25
modules (version 2, 20 bytes)
2.0 cm
minimum printable size
~20 cm
comfortable scan distance at that size
Calculated as (modules + 8 quiet-zone modules) × 0.6 mm at error-correction level M - the same maths our designer enforces.
The formula, unpacked
Modules. A QR code is a grid of small squares. The grid size is fixed by how much the code stores: a short link fits in 25×25, a WiFi login might need 29×29 or 33×33. You can't choose this - the content does.
+ 8. The specification demands an empty "quiet zone" four modules wide on every side, so a scanner can find the code's edges. Two sides × four modules = eight modules added to the width.
× 0.6 mm. The printing floor. On a heat transfer, a module thinner than 0.6 mm of ink blurs into its neighbours after pressing and washing. That number is why print minimums are hard limits, not suggestions - it's physics, not policy.
Paper rules vs. fabric rules
Most QR sizing advice online assumes paper. Fabric adds three things: the surface flexes (so marginal codes fail more often), texture breaks up fine detail (heathered fabrics especially), and the garment itself may be the background - which means the code must be darker than the shirt, or sit on a printed light panel. Our QR designer checks all of this per design and then scan-tests the finished artwork with a simulated phone camera before it can be ordered.
Questions, answered
What is the smallest QR code that will still scan?
On fabric, about 2 cm square for a short link. The real limit is the size of each little square (module): below 0.6 mm of printed ink, modules blur together and the code stops decoding. A short link makes a 25×25-module code, so (25 + 8 quiet-zone modules) × 0.6 mm = 2 cm. Longer content means more modules and a bigger minimum.
Why does a longer link need a bigger code?
A QR code grows in fixed steps called versions - 21×21 modules, then 25×25, 29×29 and so on - as the content gets longer. More modules at the same print size means each module is smaller, so dense codes hit the 0.6 mm floor at larger print sizes. Shortening the link is the single most effective way to get a smaller, cleaner code.
How far away can a QR code be scanned?
Rule of thumb: about ten times the code's size. A 5 cm chest print scans from half a metre; a 10 cm back print from a metre. Size the code for the distance people will actually stand at.
Does the quiet zone really matter?
Yes - the empty margin around a code (4 modules on every side) is part of the specification, not decoration. Phones use it to find the code's edges. Printing or embroidery butting up against the code is one of the most common reasons real-world codes fail.
Do fancy styles (dots, rounded corners) change the minimum size?
Yes. Dot-style modules only ink about 70% of each module's width, so the whole code must grow proportionally to keep every dot above 0.6 mm. Our designer recalculates the floor automatically when you change styles.
Get yours as a wash-proof transfer
Paste your link, pick a style, watch it pass the scan test - sized correctly, automatically.
Design Your QR Code