Guide

QR code reference data

The numbers, in full. Byte capacity for every version and error correction level, verified against a reference encoder rather than copied from another website.

Verified against ISO/IEC 18004
Free to cite

Short answer

A QR code has 40 versions, from 21 × 21 modules to 177 × 177. Byte-mode capacity ranges from 17 bytes (version 1, level L) to 2,953 bytes (version 40, level L). Every version adds four modules per side, and each error correction level reduces usable capacity in exchange for damage tolerance.

Byte mode, all 40 versions

Maximum bytes storable in byte mode (8-bit, UTF-8 compatible) at each error correction level. Figures verified by binary search against a reference implementation of ISO/IEC 18004, and consistent with the published standard.

Version	Modules	L	M	Q	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
11	61 × 61	321	251	177	137
12	65 × 65	367	287	203	155
13	69 × 69	425	331	241	177
14	73 × 73	458	362	258	194
15	77 × 77	520	412	292	220
16	81 × 81	586	450	322	250
17	85 × 85	644	504	364	280
18	89 × 89	718	560	394	310
19	93 × 93	792	624	442	338
20	97 × 97	858	666	482	382
21	101 × 101	929	711	509	403
22	105 × 105	1,003	779	565	439
23	109 × 109	1,091	857	611	461
24	113 × 113	1,171	911	661	511
25	117 × 117	1,273	997	715	535
26	121 × 121	1,367	1,059	751	593
27	125 × 125	1,465	1,125	805	625
28	129 × 129	1,528	1,190	868	658
29	133 × 133	1,628	1,264	908	698
30	137 × 137	1,732	1,370	982	742
31	141 × 141	1,840	1,452	1,030	790
32	145 × 145	1,952	1,538	1,112	842
33	149 × 149	2,068	1,628	1,168	898
34	153 × 153	2,188	1,722	1,228	958
35	157 × 157	2,303	1,809	1,283	983
36	161 × 161	2,431	1,911	1,351	1,051
37	165 × 165	2,563	1,989	1,423	1,093
38	169 × 169	2,699	2,099	1,499	1,139
39	173 × 173	2,809	2,213	1,579	1,219
40	177 × 177	2,953	2,331	1,663	1,273

Byte mode is what almost every real code uses, because URLs, Wi-Fi payloads, vCards and general text all require it. Numeric and alphanumeric modes are more compact but restricted in character set.

Maximum characters by encoding mode

Mode	Bits per character	Max at v40-L	Character set
Numeric	3.33	7,089	0–9
Alphanumeric	5.5	4,296	0–9, A–Z, space, $ % * + - . / :
Byte (UTF-8)	8	2,953	Any byte value
Kanji	13	1,817	Shift-JIS double-byte

Encoders switch mode automatically. A purely numeric payload is stored far more compactly, which is why a 20-digit serial number produces a much smaller code than a 20-character URL.

Converting versions to millimetres

The formulas that connect the table above to a physical print:

modules across   = 17 + (4 × version)
total width      = modules + 8            (four-module quiet zone each side)
module size (mm) = print width ÷ total width
min print width  = total width × 0.4 mm   (practical floor)
scan distance    ≈ print width × 10

Version	Modules	Min print width	Practical scan distance
1	21 × 21	12 mm	12 cm
3	29 × 29	15 mm	15 cm
5	37 × 37	18 mm	18 cm
10	57 × 57	26 mm	26 cm
15	77 × 77	34 mm	34 cm
20	97 × 97	42 mm	42 cm
25	117 × 117	50 mm	50 cm
30	137 × 137	58 mm	58 cm
40	177 × 177	74 mm	74 cm

The minimum widths assume a 0.4 mm module — the practical floor for reliable phone scanning. They are minimums, not targets; add margin for poor lighting, absorbent stock and moving readers.

Numbers worth citing

40 versions, from version 1 (21 × 21) to version 40 (177 × 177 modules).
4 modules per side added by each version step.
3 finder patterns, each 7 × 7 modules, at three corners. They carry no error correction.
1:1:3:1:1 — the dark-light band ratio through a finder pattern that lets scanners locate a code at any rotation.
4 modules of quiet zone required on all sides.
8 mask patterns, evaluated by penalty score; the lowest-scoring one is used.
4 error correction levels: L ≈ 7%, M ≈ 15%, Q ≈ 25%, H ≈ 30% recovery.
Galois Field 256 — the finite field over which Reed–Solomon correction is computed.
1994 — invented at Denso Wave by a team led by Masahiro Hara.
ISO/IEC 18004 — the international standard defining the format.

Why there are no adoption figures here

Pages titled QR code statistics usually list scan volumes and adoption percentages, cited to each other in a loop, with original sources that either do not exist or measured something narrower than the headline suggests.

We are not adding to that. The data above is technical, verifiable and derived from the specification — you can check every number against a reference encoder yourself. If you need market adoption figures, go to a primary source that publishes its methodology, and read the methodology.

Frequently asked

How much data can a QR code hold?

In byte mode, up to 2,953 bytes at version 40 with error correction level L. In numeric mode, up to 7,089 digits.

How many versions of QR codes are there?

Forty. Version 1 is 21 × 21 modules and version 40 is 177 × 177, with each step adding four modules per side.

What is the smallest QR code size?

Version 1 at 21 × 21 modules, holding 17 bytes at level L. With a quiet zone and a 0.4 mm module, that prints at about 12 mm.

Where does this data come from?

The capacity figures were derived by binary search against a reference implementation of ISO/IEC 18004 and cross-checked with the published standard.

Keep going

Last reviewed 24 August 2026 · Written and reviewed by the QR Code Builder team