Sheet metal · US Standard · 15 U.S.C. 206 (wrought iron basis)

U.S. Standard Gauge Gauge Chart — Thickness in Inches and Millimetres

Name: U.S. Standard Gauge sheet gauge thicknesses
Creator: ShopMath

https://shopmath.org/gauges/us-standard · data verified August 1, 2026

U.S. Standard Gauge runs from 0000000 gauge at 0.5000 in (12.700 mm) down to 38 gauge at 0.0063 in (0.159 mm), 45 sizes in all. The 1893 statutory gauge, as enacted, on a wrought-iron density basis.

Gauges: 45
Thickest: 0000000 ga
Thinnest: 38 ga
System: 15 U.S.C. 206 (wrought iron basis)

Every US Standard Sheet Gauge and Its Thickness

45 gauges on the 15 U.S.C. 206 (wrought iron basis), thickest first. A lower gauge number is thicker sheet, and the steps are geometric rather than even.

U.S. Standard Gauge sheet gauge thicknesses
Property	Thickness		Weight
Gauge	in	mm	lb/ft²	kg/m²
0000000 ga	0.5000	12.700	20.00	97.65
000000 ga	0.4688	11.906	18.75	91.55
00000 ga	0.4375	11.113	17.50	85.44
0000 ga	0.4063	10.319	16.25	79.33
000 ga	0.3750	9.525	15.00	73.24
00 ga	0.3438	8.731	13.75	67.13
0 ga	0.3125	7.938	12.50	61.03
1 ga	0.2813	7.144	11.25	54.93
2 ga	0.2656	6.747	10.63	51.88
3 ga	0.2500	6.350	10.00	48.82
4 ga	0.2344	5.953	9.38	45.77
5 ga	0.2188	5.556	8.75	42.72
6 ga	0.2031	5.159	8.13	39.67
7 ga	0.1875	4.763	7.50	36.62
8 ga	0.1719	4.366	6.88	33.57
9 ga	0.1563	3.969	6.25	30.52
10 ga	0.1406	3.572	5.63	27.46
11 ga	0.1250	3.175	5.00	24.41
12 ga	0.1094	2.778	4.38	21.36
13 ga	0.0938	2.381	3.75	18.31
14 ga	0.0781	1.984	3.13	15.26
15 ga	0.0703	1.786	2.81	13.73
16 ga	0.0625	1.587	2.50	12.21
17 ga	0.0563	1.429	2.25	10.99
18 ga	0.0500	1.270	2.00	9.77
19 ga	0.0438	1.111	1.75	8.54
20 ga	0.0375	0.953	1.50	7.32
21 ga	0.0344	0.873	1.38	6.71
22 ga	0.0313	0.794	1.25	6.10
23 ga	0.0281	0.714	1.13	5.49
24 ga	0.0250	0.635	1.00	4.88
25 ga	0.0219	0.556	0.88	4.27
26 ga	0.0188	0.476	0.75	3.66
27 ga	0.0172	0.437	0.69	3.36
28 ga	0.0156	0.397	0.63	3.05
29 ga	0.0141	0.357	0.56	2.75
30 ga	0.0125	0.318	0.50	2.44
31 ga	0.0109	0.278	0.44	2.14
32 ga	0.0102	0.258	0.41	1.98
33 ga	0.0094	0.238	0.38	1.83
34 ga	0.0086	0.218	0.34	1.68
35 ga	0.0078	0.198	0.31	1.53
36 ga	0.0070	0.179	0.28	1.37
37 ga	0.0066	0.169	0.27	1.30
38 ga	0.0063	0.159	0.25	1.22

Thicknesses are nominal, before mill tolerance. Weights are for the base material at the nominal thickness.

Sources and Method for the US Standard Gauge Chart

U.S. Standard Gauge thicknessescomputed

15 U.S.C. 206 (Act of Mar. 3, 1893, ch. 221, 27 Stat. 746) — U.S. Standard Gauge for sheet and plate iron and steel; 15 U.S.C. 206 statutory weights; MSG (41.82 lb/ft2 per inch), galvanized zinc allowance, and Brown & Sharpe formula per docs/research/data-sourcing.md §3.7

Verified against Wikipedia Sheet metal, Standard sheet metal gauges table (CC BY-SA 4.0) — 137/137 checks passed at 0.05 mil

Computed from the standard's formulas, then checked against published tables.

Assumptions

Thicknesses are nominal; mill tolerance is not part of the gauge definition.
Gauge numbers here index the 15 U.S.C. 206 (wrought iron basis). The same number on another material is a different thickness.
Dataset scope: EXCLUDED: stainless steel (genuinely ambiguous convention, only one source in hand), zinc, copper, brass, steel tube wall.

Data last verified

August 1, 2026

How this data is built and checked →

How to Cite This US Standard Gauge Chart

Citation

ShopMath. "U.S. Standard Gauge Gauge Chart — Thickness in Inches and Millimetres." ShopMath, verified August 1, 2026, https://shopmath.org/gauges/us-standard

BibTeX

@misc{shopmath-gauges-us-standard,
  title        = {U.S. Standard Gauge Gauge Chart — Thickness in Inches and Millimetres},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/gauges/us-standard}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/gauges/us-standard

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