QR code size for packaging

Size packaging QR codes at 2–3 cm for in-hand scanning and about 5 cm if shoppers scan from the shelf edge. On curved containers add roughly 25%, because modules near the label's edges foreshorten. Use error correction Q: transit scuffing is the localised damage EC exists to repair.

Two scanning moments

Packaging gets scanned at two distances, and the design should decide which one it is for:

Context	Distance	Flat surface	Cylinder (+25%)
Pack picked up, in the hand	20–30 cm	2–3 cm	2.5–3.8 cm
Read at the shelf edge, not picked up	50 cm	5 cm	6.3 cm

Most packs are picked up before scanning, so 2–3 cm on a flat face is the standard answer. Size for the shelf only if the code's job is to win the pick-up (a comparison tool or price-check use case), in which case 5 cm is the price of being scanned at all.

The curvature penalty

On a cylinder (jars, bottles, cans, tubes) the label wraps, and modules away from the centreline tilt progressively out of the camera's plane. The pattern the camera sees is compressed at the sides, and past a point the corner finder patterns distort enough that detection fails.

Two working rules:

Add about 25% to the flat-surface size, so the central, usable arc still satisfies the distance maths.
Keep the whole code within an arc where the surface stays close to flat, on small diameters that can mean the code does not fit at all, and the honest fix is moving it to the lid, the base or a hang tag. The full geometry, with diameter thresholds, is in QR codes on cylindrical packaging.

Error correction and wear

Packs are scuffed in transit, stacked, gripped and chilled. That is localised damage, so EC Q (25% recovery) is the right default for packaging, one of the few surfaces where the density cost is clearly worth it. Pair it with the substrate floors from the size pillar: 0.4 mm modules on coated board, 0.5 mm on uncoated or kraft-style stock.

Payload discipline

Packaging codes tend to accumulate jobs: marketing page, ingredients, registration. Keep one code, one short URL, and let the landing page route; a long URL pushes the version up and undoes your sizing. What the code should link to, and how packs handle regulated content like GS1 Digital Link, is covered in QR codes on product packaging and the product label guide.

Before the print run: size calculator with the real payload, decode check on the final artwork, and a scan test on a filled pack, curves behave differently under label tension than on a flat proof.

FAQ

How big should a QR code be on product packaging?

2–3 cm on a flat face for packs people pick up, around 5 cm if shoppers should scan from the shelf without picking it up. Add roughly 25% on curved containers such as bottles and jars.

Why does my QR code scan on the flat proof but not on the bottle?

Curvature. Once the label wraps, modules near the edges of the code tilt away from the camera and compress. Enlarge the code by about a quarter, centre it on the flattest arc, or move it to the lid or a flat panel.

What error correction level should packaging use?

Q. Transit scuffs, stacking marks and grip wear are localised damage that 25% error correction genuinely repairs. Combine it with modules of at least 0.4 mm so print quality does not eat the margin.

Where is the best place for a QR code on a curved container?

The flattest available surface: a front or back label panel on large diameters, otherwise the lid, the base or a hang tag. Small-diameter tubes and bottles often cannot carry a scannable wrapped code at all.