What size does a 3D printed QR code need to be

By Tiehl Roberto Matías · 7 min read · Updated 25 October 2026

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«How big should I make it?» is the question that comes up most and gets answered worst, usually with a single number and without anyone asking what nozzle you print with. The minimum size is not an opinion: it comes out of a multiplication with three numbers in it.

The three numbers you need

To know how big the piece has to be you need to know, in this order:

1. How many modules your code has. That depends on the link you put in, not on the piece.
2. Your nozzle diameter. Almost always 0.4 mm, sometimes 0.6.
3. How far away it will be scanned from. This pushes the minimum up, never down.

Number 1: how many modules your code has

The module count is decided by how much information goes in. A QR code has 40 versions and each one adds four modules a side: version 1 is 21 × 21 and version 40 is 177 × 177. The formula is modules = 17 + 4 × version.

What decides the version is how many characters you put in and which error correction level you pick. This table says how many characters fit in each version, worked out with the encoder of this same site:

Version	Modules	Level L	Level M	Level Q	Level H
1	21 × 21	17	14	11	7
2	25 × 25	32	26	20	14
3	29 × 29	53	42	32	24
4	33 × 33	78	62	46	34
5	37 × 37	106	84	60	44
6	41 × 41	134	106	74	58
7	45 × 45	154	122	86	64
8	49 × 49	192	152	108	84
9	53 × 53	230	180	130	98
10	57 × 57	271	213	151	119

Read it left to right: find your character count in the column for your level and see which version you land on. With 40 characters at level M you are on version 4, 33 modules a side.

Number 2: the minimum module size

Here is the physical limit. The printer lays down a bead of material roughly as wide as the nozzle diameter. For a module to come out as a square with straight edges, rather than as a stretched blob, two beads have to fit inside it.

Nozzle	Minimum module	Comfortable module
0.2 mm	0.4 mm	0.6 mm
0.4 mm	0.8 mm	1.0 mm
0.6 mm	1.2 mm	1.5 mm
0.8 mm	1.6 mm	2.0 mm

All of this table is filament printing. In resin there is no nozzle and the limit comes from the camera that will read the code rather than from the machine: the minimum module drops to about three tenths of a millimetre. The numbers are in the resin guide (in Spanish).

There is a second minimum that almost nobody looks at and that sometimes outranks this one: the one imposed by layer height, because the relief can only be a whole number of layers. That is in the layer height guide (in Spanish). The «comfortable» column is the one actually worth using. The minimum works with the printer well calibrated and the first layer at exactly its height; the comfortable value also works on the days the machine is not at its best.

The formula

side of the piece = (modules + 8) × minimum module

The 8 modules added on are the quiet zone: four on each side, required by the standard. Without them the reader cannot find where the code ends.

If you would rather not do the arithmetic by hand, the size calculator (in Spanish) does it with your exact content: you paste the link, pick your nozzle and it gives you the millimetres.

Worked table for a 0.4 mm nozzle

Version	Modules	Minimum (0.8 mm)	Comfortable (1.0 mm)
1	21	23.2 mm	29.0 mm
2	25	26.4 mm	33.0 mm
3	29	29.6 mm	37.0 mm
4	33	32.8 mm	41.0 mm
5	37	36.0 mm	45.0 mm
6	41	39.2 mm	49.0 mm
7	45	42.4 mm	53.0 mm
8	49	45.6 mm	57.0 mm
10	57	52.0 mm	65.0 mm

Worked table for a 0.6 mm nozzle

Version	Modules	Minimum (1.2 mm)	Comfortable (1.5 mm)
1	21	34.8 mm	43.5 mm
2	25	39.6 mm	49.5 mm
3	29	44.4 mm	55.5 mm
4	33	49.2 mm	61.5 mm
5	37	54.0 mm	67.5 mm
6	41	58.8 mm	73.5 mm
8	49	68.4 mm	85.5 mm
10	57	78.0 mm	97.5 mm

Number 3: the reading distance

So far we have worked out the minimum for the printer to be able to reproduce the code. What is missing is the minimum for the camera to see it from wherever people will be standing.

The rule of thumb used in signage works here too:

maximum reading distance ≈ 10 × side of the code

Side of the code	Reads comfortably up to	Typical use
30 mm	30 cm	Keychain, in the hand
50 mm	50 cm	On the counter
90 mm	90 cm	Stand on the table
150 mm	1.5 m	Wall plate
300 mm	3 m	Shop window, sign

It is a conservative rule: a modern phone in good light reaches considerably further. But it is built for the realistic worst case, which is somebody with an old phone in mediocre light, and that is exactly the case you have to cover once the piece is printed and screwed to a wall.

If the size you end up with does not fit on your printer's bed, read the guide to oversized codes (in Spanish) before cutting the piece into chunks: usually you do not need to, and when you do there are cuts that cannot be made.

The final size

Take the two numbers — the one from the nozzle and the one from the distance — and keep the larger of the two. That is your size.

A worked example. You want a plate for the workshop wall linking to a machine's manual, and it will be scanned from a metre and a half away:

• The shortened link is 38 characters at level M → version 4, 33 modules.
• With a 0.4 mm nozzle and a comfortable 1.0 mm module → 41 mm minimum for printing.
• To read at 1.5 m you need 150 mm of code.
• The second one wins: the plate is made 150 mm, and the modules end up at 3.6 mm each, comfortable even for a 0.8 nozzle.

There is one case where this calculation cannot be applied as it stands, because the size is decided in advance: the 3D printed business card (in Spanish). There the piece measures whatever a pocket measures, and the only variable left is shortening the link until the modules fit. And with even less room, on a pet collar tag (in Spanish), where the size is decided by the animal wearing it.