Convert gauge numbers to mm / inch / weight for steel, galvanized, stainless steel, aluminum, and copper.
Covers US Standard (USS), Brown & Sharpe (B&S), and Galvanized Steel gauge systems.
🔄 Gauge ↔ Thickness Converter
Select material, enter gauge number — instant mm / inch / kg/m² results.
—
Thickness (mm)
—
Thickness (inch)
—
Weight kg/m²
—
Weight lbs/ft²
—
Material / Standard
Carbon Steel & Galvanized Steel — US Standard Gauge (USS)
Gauge #
mm
Inch
Fraction
kg/m²
lbs/ft²
Common Use
Visual
3
6.073
0.2391"
15/64"
47.67
9.76
Heavy structural
4
5.695
0.2242"
7/32"
44.71
9.16
Heavy structural
5
5.314
0.2092"
13/64"
41.72
8.55
Heavy plate
6
4.935
0.1943"
3/16"
38.74
7.94
Heavy plate
7
4.554
0.1793"
11/64"
35.75
7.33
Heavy duty fab
8
4.176
0.1644"
5/32"
32.78
6.72
Heavy enclosures
9
3.797
0.1495"
9/64"
29.81
6.11
Tanks, vessels
10
3.416
0.1345"
9/64"
26.82
5.50
Structural fabrication
11
3.038
0.1196"
1/8"
23.85
4.89
Heavy machine parts
12
2.657
0.1046"
7/64"
20.86
4.27
Machine enclosures
13
2.278
0.0897"
3/32"
17.88
3.66
Heavy HVAC
14
1.897
0.0747"
5/64"
14.90
3.05
Structural, roofing
15
1.709
0.0673"
1/16"
13.42
2.75
HVAC, ductwork
16
1.519
0.0598"
1/16"
11.93
2.44
General fabrication
17
1.367
0.0538"
3/64"
10.73
2.20
Light fabrication
18
1.214
0.0478"
3/64"
9.53
1.95
Enclosures, panels
19
1.062
0.0418"
1/32"
8.34
1.71
HVAC light ductwork
20
0.912
0.0359"
1/32"
7.16
1.47
Appliance panels
21
0.836
0.0329"
1/32"
6.56
1.34
Light sheet metal
22
0.759
0.0299"
1/32"
5.96
1.22
Light sheet, trims
23
0.683
0.0269"
—
5.36
1.10
Thin sheet
24
0.607
0.0239"
—
4.77
0.98
Thin sheet, cans
25
0.531
0.0209"
—
4.17
0.85
Packaging
26
0.455
0.0179"
—
3.57
0.73
Roofing, flashing
27
0.417
0.0164"
—
3.27
0.67
Thin roofing
28
0.378
0.0149"
—
2.97
0.61
Very thin sheet
29
0.343
0.0135"
—
2.69
0.55
Ultra thin
30
0.305
0.0120"
—
2.39
0.49
Ultra thin foil
31
0.274
0.0108"
—
2.15
0.44
Foil
32
0.257
0.0101"
—
2.02
0.41
Foil
33
0.241
0.0095"
—
1.89
0.39
Foil
34
0.229
0.0090"
—
1.80
0.37
Foil
35
0.213
0.0084"
—
1.67
0.34
Very thin foil
36
0.198
0.0078"
—
1.55
0.32
Shim stock
Stainless Steel — US Standard Gauge (USS) — Grades 304 / 316 / 430
🔍 No results found. Please try a different keyword.
USS = United States Standard gauge (carbon & stainless steel) |
B&S = Brown & Sharpe gauge (aluminum, copper, brass) |
Higher gauge # = Thinner material
Densities used: Carbon steel 7.85 g/cm³ · Stainless steel 7.93 g/cm³ · Aluminum 2.71 g/cm³ · Copper 8.96 g/cm³.
Source: ASTM A480, ASTM A666, Machinery's Handbook 31st Ed, AWS D1.1. Highlighted rows = most commonly ordered gauges.
Sheet Metal Gauge FAQ
What does gauge mean in sheet metal?+
Sheet metal gauge is a numbering system specifying thickness. Higher gauge number = thinner material. Example: 18 gauge steel = 1.214mm, 22 gauge = 0.759mm. Different materials use different gauge standards — USS for steel, B&S for aluminum and copper — so the same number gives different thicknesses.
What is the most common sheet metal gauge used in construction?+
Most common gauges: 16 gauge (1.519mm) and 18 gauge (1.214mm) for HVAC, enclosures, and general fabrication. 14 gauge (1.897mm) for structural work. 20 gauge (0.912mm) for light appliance panels. For stainless steel, 16 and 18 gauge are standard for kitchen equipment. For galvanized roofing panels from Chinese mills, common metric sizes are 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1.0mm.
What gauge is 1mm, 1.5mm, and 2mm steel?+
Approximate gauge equivalents for carbon steel: 1.0mm ≈ 19–20 gauge (18ga = 1.214mm, 19ga = 1.062mm) · 1.2mm ≈ 18 gauge · 1.5mm ≈ 16 gauge (16ga = 1.519mm) · 2.0mm ≈ 14 gauge (14ga = 1.897mm, close but not exact) · 3.0mm ≈ 11 gauge (11ga = 3.038mm). Chinese steel mills always specify in millimeters — confirm exact mm thickness when ordering.
Why are steel and aluminum gauges different for the same number?+
Steel uses US Standard (USS) gauge; aluminum and copper use Brown & Sharpe (B&S). Example: 18 gauge steel = 1.214mm but 18 gauge aluminum = 1.024mm. Always specify material when ordering by gauge. In international trade, specifying exact thickness in mm is strongly recommended.
What gauge is galvanized steel roofing typically?+
Galvanized steel roofing panels (GI / PPGI) are most commonly supplied at 0.4mm–0.6mm in China's metric system, equivalent to approximately 25–28 gauge (USS). Light residential roofing uses 0.3mm–0.5mm; commercial/industrial roofing uses 0.5mm–1.0mm. Pre-painted galvanized (PPGI) is most commonly ordered in 0.4mm, 0.5mm, 0.6mm thicknesses with zinc coating Z80–Z275 and PE/SMP/PVDF paint system.
Need Steel Sheet or Coil? We Can Source It.
Zhongtang Metal supplies galvanized steel, PPGI, cold rolled, and stainless steel sheets and coils to 150+ countries. Factory-direct pricing with flexible MOQ.
